About this index & how it's been checked
The Aging Vulnerability Index (AVI) is this platform's own construction, modeled on the CDC/ATSDR Social Vulnerability Index methodology but not a CDC product and not independently validated. It combines Census ACS data on the population 65 and older — demographic aging pressure, economic precarity, health/disability/isolation, and housing/transportation burden — into a single percentile ranking of U.S. counties. The underlying inputs are official Census data; the index construction and weighting are this platform's own.
Reference-county check
A face-validity check against real counties with well-documented age profiles — the same method used to calibrate this platform's seasonal-community threshold. Higher percentile = more aging-vulnerable.
- ✓ Sumter County, FL — 79.8th percentile (expected HIGH, The Villages — often cited as the oldest-median-age U.S. county)
- ✓ Charlotte County, FL — 90.8th percentile (expected HIGH, Retirement destination)
- ✓ Citrus County, FL — 88.1th percentile (expected HIGH, Retirement destination)
- ✓ Highlands County, FL — 95.9th percentile (expected HIGH, Retirement destination)
- ✓ Brazos County, TX — 17.0th percentile (expected LOW, Texas A&M)
- ✓ Story County, IA — 8.9th percentile (expected LOW, Iowa State)
- ✓ Whitman County, WA — 10.3th percentile (expected LOW, Washington State University)
- ✓ Tompkins County, NY — 7.6th percentile (expected LOW, Cornell)
Highest / lowest AVI by county population
Under 50,000
Highest
- Catron County, NM — 100.0th pctile (pop. 3,743)
- De Baca County, NM — 99.9th pctile (pop. 1,576)
- Ozark County, MO — 99.8th pctile (pop. 8,873)
- Scott County, VA — 99.6th pctile (pop. 21,479)
- Harney County, OR — 99.6th pctile (pop. 7,499)
Lowest
- Martin County, TX — 0.0th pctile (pop. 5,218)
- Jim Hogg County, TX — 0.1th pctile (pop. 4,727)
- Haskell County, KS — 0.1th pctile (pop. 3,641)
- Hanson County, SD — 0.1th pctile (pop. 3,472)
- Trousdale County, TN — 0.2th pctile (pop. 11,957)
50,000-99,999
Highest
- Nye County, NV — 96.7th pctile (pop. 54,344)
- Gila County, AZ — 96.7th pctile (pop. 53,795)
- Raleigh County, WV — 96.0th pctile (pop. 73,195)
- Wilkes County, NC — 95.6th pctile (pop. 65,935)
- Pittsylvania County, VA — 94.0th pctile (pop. 59,856)
Lowest
- Oldham County, KY — 0.0th pctile (pop. 69,257)
- Eagle County, CO — 0.2th pctile (pop. 55,135)
- Lincoln County, SD — 0.5th pctile (pop. 70,638)
- Johnson County, MO — 0.9th pctile (pop. 54,732)
- Lafayette County, MS — 1.3th pctile (pop. 58,327)
100,000-299,999
Highest
- Highlands County, FL — 95.9th pctile (pop. 105,702)
- Mohave County, AZ — 93.9th pctile (pop. 220,517)
- Douglas County, OR — 93.0th pctile (pop. 112,072)
- Charlotte County, FL — 90.8th pctile (pop. 201,064)
- Indian River County, FL — 90.3th pctile (pop. 166,936)
Lowest
- Union County, NC — 0.8th pctile (pop. 250,958)
- Scott County, MN — 1.1th pctile (pop. 154,557)
- Williamson County, TN — 1.2th pctile (pop. 260,351)
- St. Mary's County, MD — 1.3th pctile (pop. 115,126)
- Dallas County, IA — 1.5th pctile (pop. 107,968)
300,000 and higher
Highest
- Pinellas County, FL — 90.1th pctile (pop. 963,481)
- Collier County, FL — 89.9th pctile (pop. 398,291)
- Marion County, FL — 87.1th pctile (pop. 400,078)
- Lee County, FL — 86.1th pctile (pop. 817,666)
- Palm Beach County, FL — 85.0th pctile (pop. 1,533,806)
Lowest
- Hamilton County, IN — 0.6th pctile (pop. 365,056)
- Prince William Count, VA — 2.1th pctile (pop. 488,880)
- Davis County, UT — 2.1th pctile (pop. 370,924)
- Douglas County, CO — 2.2th pctile (pop. 377,150)
- Loudoun County, VA — 2.4th pctile (pop. 432,998)
MT — Aging Vulnerability Index
Candidate index, not validated against ground truth — 2020–2024 ACS 5-year
MT — Aging Vulnerability Index by county
Where this is
Shading: Aging Vulnerability Index
Lower (0 to 18)Lower-middle (20 to 38)Middle (40 to 58)Upper-middle (60 to 78)Higher (80 to 100)
Each unit is shaded by its Aging Vulnerability Index value and grouped into equal-count bands (quantiles) against the other units shown — lighter = lower, darker = higher. It ranks position among the units in view; it does not grade places, and the ranges shift with which units are shown.
The map is bounded to this parent geography — it shows the selected unit among its own siblings only, the same depth rule the drill-down uses. Shading ranks position on the measure among the units shown; it does not grade places.
Median county: 50th percentile (among counties in MT).
These counties span the 0th percentile to the 100th percentile. The width of that range is the internal disparity.
Dawson County is marked below — Well below the median.
Widest spread across these counties: Demographic Aging Pressure — this theme most separates the higher- and lower-ranked counties here.
AVI ranks each county's position relative to a comparison set; it is not averaged into one number for the area, because percentiles do not average meaningfully. The distribution — median, range, and shape below — is the summary.
Dawson County — by county subdivision
Median county subdivision: 54th percentile (among county subdivisions in MT).
These county subdivisions span the 40th percentile to the 67th percentile. The width of that range is the internal disparity.
Widest spread across these county subdivisions: Health, Disability & Isolation — this theme most separates the higher- and lower-ranked county subdivisions here.
AVI ranks each county subdivision's position relative to a comparison set; it is not averaged into one number for the area, because percentiles do not average meaningfully. The distribution — median, range, and shape below — is the summary.
Well above the median — 12 counties (80th–100th percentile)
Golden Valley County — 100th percentile — Well above the median 6 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure ‡ (above), Health, Disability & Isolation ‡ (well above) and Social Isolation ‡ (well above); near the median on Economic Precarity, 65+ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Sanders County — 98th percentile — Well above the median 3 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above), Economic Precarity, 65+ (above) and Health, Disability & Isolation ‡ (well above); near the median on Social Isolation; below the median on Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Prairie County — 96th percentile — Well above the median 4 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure ‡ (well above), Economic Precarity, 65+ ‡ (well above) and Social Isolation (well above); below the median on Health, Disability & Isolation ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Musselshell County — 95th percentile — Well above the median 4 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (above), Economic Precarity, 65+ (above), Health, Disability & Isolation ‡ (above) and Social Isolation (well above); near the median on Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Daniels County — 93rd percentile — Well above the median 4 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above), Housing & Transportation, 65+ ‡ (well above) and Social Isolation ‡ (well above); near the median on Economic Precarity, 65+ and Health, Disability & Isolation ‡.
‡ theme includes at least one flagged input.
Liberty County — 91st percentile — Well above the median 4 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (above), Economic Precarity, 65+ ‡ (well above), Housing & Transportation, 65+ ‡ (well above) and Social Isolation (well above); below the median on Health, Disability & Isolation ‡.
‡ theme includes at least one flagged input.
Lincoln County — 89th percentile — Well above the median 3 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above), Economic Precarity, 65+ (above) and Health, Disability & Isolation ‡ (well above); below the median on Housing & Transportation, 65+ ‡ and Social Isolation.
‡ theme includes at least one flagged input.
Powder River County — 87th percentile — Well above the median 5 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above), Health, Disability & Isolation ‡ (above) and Social Isolation (above); below the median on Economic Precarity, 65+ ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Ravalli County — 85th percentile — Well above the median 2 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (above), Health, Disability & Isolation ‡ (well above) and Housing & Transportation, 65+ ‡ (above); near the median on Social Isolation; below the median on Economic Precarity, 65+.
‡ theme includes at least one flagged input.
Mineral County — 84th percentile — Well above the median 3 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (above), Economic Precarity, 65+ (above), Housing & Transportation, 65+ ‡ (above) and Social Isolation (above); near the median on Health, Disability & Isolation ‡.
‡ theme includes at least one flagged input.
Deer Lodge County — 82nd percentile — Well above the median 4 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (above), Economic Precarity, 65+ (above) and Social Isolation (well above); near the median on Health, Disability & Isolation ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Fergus County — 80th percentile — Well above the median 3 of 12 flagged View by census tract →
Driven by Economic Precarity, 65+ (well above), Housing & Transportation, 65+ ‡ (above) and Social Isolation (above); near the median on Demographic Aging Pressure and Health, Disability & Isolation ‡.
‡ theme includes at least one flagged input.
Above the median — 11 counties (60th–80th percentile)
Chouteau County — 78th percentile — Above the median 4 of 12 flagged View by census tract →
Driven by Economic Precarity, 65+ (above), Health, Disability & Isolation ‡ (well above) and Social Isolation (well above); near the median on Demographic Aging Pressure; below the median on Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Pondera County — 75th percentile — Above the median 3 of 12 flagged View by census tract →
Driven by Economic Precarity, 65+ (well above) and Social Isolation (well above); near the median on Demographic Aging Pressure, Health, Disability & Isolation ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Wheatland County — 75th percentile — Above the median 3 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (above), Economic Precarity, 65+ ‡ (well above) and Social Isolation (above); below the median on Health, Disability & Isolation ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Lake County — 73rd percentile — Above the median 1 of 12 flagged View by census tract →
Driven by Economic Precarity, 65+ (above), Health, Disability & Isolation ‡ (well above) and Housing & Transportation, 65+ (above); near the median on Demographic Aging Pressure; below the median on Social Isolation.
‡ theme includes at least one flagged input.
Treasure County — 71st percentile — Above the median 7 of 12 flagged View by census tract →
Driven by Health, Disability & Isolation ‡ (well above) and Social Isolation ‡ (above); near the median on Demographic Aging Pressure ‡ and Economic Precarity, 65+ ‡; below the median on Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Carter County — 69th percentile — Above the median 4 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above) and Social Isolation (above); near the median on Housing & Transportation, 65+ ‡; below the median on Economic Precarity, 65+ ‡ and Health, Disability & Isolation ‡.
‡ theme includes at least one flagged input.
Teton County — 67th percentile — Above the median 3 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (above), Economic Precarity, 65+ (above) and Housing & Transportation, 65+ ‡ (above); below the median on Health, Disability & Isolation ‡ and Social Isolation.
‡ theme includes at least one flagged input.
McCone County — 64th percentile — Above the median 4 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above) and Social Isolation (well above); below the median on Economic Precarity, 65+ ‡, Health, Disability & Isolation ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Rosebud County — 64th percentile — Above the median 2 of 12 flagged View by census tract →
Driven by Economic Precarity, 65+ (well above), Health, Disability & Isolation ‡ (well above), Housing & Transportation, 65+ ‡ (above) and Social Isolation (above); below the median on Demographic Aging Pressure.
‡ theme includes at least one flagged input.
Garfield County — 62nd percentile — Above the median 4 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above) and Economic Precarity, 65+ ‡ (above); near the median on Health, Disability & Isolation ‡; below the median on Housing & Transportation, 65+ ‡ and Social Isolation ‡.
‡ theme includes at least one flagged input.
Meagher County — 60th percentile — Above the median 4 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above), Economic Precarity, 65+ ‡ (well above) and Social Isolation ‡ (well above); below the median on Health, Disability & Isolation and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Near the median — 11 counties (40th–60th percentile)
Sheridan County — 58th percentile — Near the median 3 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (above) and Social Isolation (well above); near the median on Housing & Transportation, 65+ ‡; below the median on Economic Precarity, 65+ and Health, Disability & Isolation ‡.
‡ theme includes at least one flagged input.
Petroleum County — 56th percentile — Near the median 5 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure ‡ (above) and Health, Disability & Isolation ‡ (well above); near the median on Economic Precarity, 65+ ‡ and Social Isolation ‡; below the median on Housing & Transportation, 65+.
‡ theme includes at least one flagged input.
Valley County — 55th percentile — Near the median 3 of 12 flagged View by census tract →
Driven by Housing & Transportation, 65+ ‡ (well above); near the median on Demographic Aging Pressure and Social Isolation; below the median on Economic Precarity, 65+ and Health, Disability & Isolation ‡.
‡ theme includes at least one flagged input.
Stillwater County — 53rd percentile — Near the median 1 of 12 flagged View by census tract →
Driven by Health, Disability & Isolation (above) and Housing & Transportation, 65+ ‡ (above); near the median on Demographic Aging Pressure; below the median on Economic Precarity, 65+ and Social Isolation.
‡ theme includes at least one flagged input.
Granite County — 51st percentile — Near the median 3 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (above); near the median on Economic Precarity, 65+ and Housing & Transportation, 65+ ‡; below the median on Health, Disability & Isolation ‡ and Social Isolation.
‡ theme includes at least one flagged input.
Phillips County — 49th percentile — Near the median 5 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (above) and Social Isolation ‡ (above); near the median on Economic Precarity, 65+ ‡; below the median on Health, Disability & Isolation ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Big Horn County — 47th percentile — Near the median 4 of 12 flagged View by census tract →
Driven by Economic Precarity, 65+ (well above), Health, Disability & Isolation ‡ (well above) and Housing & Transportation, 65+ ‡ (well above); near the median on Social Isolation; below the median on Demographic Aging Pressure.
‡ theme includes at least one flagged input.
Carbon County — 45th percentile — Near the median 4 of 12 flagged View by census tract →
Driven by Health, Disability & Isolation ‡ (above); near the median on Demographic Aging Pressure; below the median on Economic Precarity, 65+, Housing & Transportation, 65+ ‡ and Social Isolation.
‡ theme includes at least one flagged input.
Park County — 42nd percentile — Near the median 4 of 12 flagged View by census tract →
Driven by Health, Disability & Isolation ‡ (above); near the median on Demographic Aging Pressure and Housing & Transportation, 65+ ‡; below the median on Economic Precarity, 65+ and Social Isolation.
‡ theme includes at least one flagged input.
Sweet Grass County — 42nd percentile — Near the median 4 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above) and Social Isolation (above); below the median on Economic Precarity, 65+ ‡, Health, Disability & Isolation ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Madison County — 40th percentile — Near the median 3 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above); near the median on Health, Disability & Isolation ‡; below the median on Economic Precarity, 65+, Housing & Transportation, 65+ ‡ and Social Isolation.
‡ theme includes at least one flagged input.
Below the median — 11 counties (20th–40th percentile)
Cascade County — 38th percentile — Below the median 1 of 12 flagged View by census tract →
Driven by Economic Precarity, 65+ (above) and Housing & Transportation, 65+ (above); near the median on Health, Disability & Isolation ‡; below the median on Demographic Aging Pressure and Social Isolation.
‡ theme includes at least one flagged input.
Broadwater County — 36th percentile — Below the median 3 of 12 flagged View by census tract →
Driven by Health, Disability & Isolation ‡ (above); near the median on Social Isolation; below the median on Demographic Aging Pressure, Economic Precarity, 65+ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Blaine County — 35th percentile — Below the median 3 of 12 flagged View by census tract →
Driven by Economic Precarity, 65+ (well above) and Health, Disability & Isolation ‡ (well above); near the median on Social Isolation; below the median on Demographic Aging Pressure and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Glacier County — 33rd percentile — Below the median 3 of 12 flagged View by census tract →
Driven by Economic Precarity, 65+ (well above) and Health, Disability & Isolation ‡ (well above); near the median on Housing & Transportation, 65+ ‡; below the median on Demographic Aging Pressure and Social Isolation.
‡ theme includes at least one flagged input.
Silver Bow County — 31st percentile — Below the median 1 of 12 flagged View by census tract →
Driven by Economic Precarity, 65+ (above) and Housing & Transportation, 65+ (well above); below the median on Demographic Aging Pressure, Health, Disability & Isolation ‡ and Social Isolation.
‡ theme includes at least one flagged input.
Wibaux County — 29th percentile — Below the median 6 of 12 flagged View by census tract →
Driven by Social Isolation ‡ (above); near the median on Economic Precarity, 65+ ‡; below the median on Demographic Aging Pressure ‡, Health, Disability & Isolation ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Flathead County — 27th percentile — Below the median 1 of 12 flagged View by census tract →
Driven by Health, Disability & Isolation ‡ (above) and Housing & Transportation, 65+ (well above); below the median on Demographic Aging Pressure, Economic Precarity, 65+ and Social Isolation.
‡ theme includes at least one flagged input.
Hill County — 25th percentile — Below the median 3 of 12 flagged View by census tract →
Driven by Economic Precarity, 65+ (well above) and Housing & Transportation, 65+ ‡ (well above); near the median on Health, Disability & Isolation ‡; below the median on Demographic Aging Pressure and Social Isolation.
‡ theme includes at least one flagged input.
Yellowstone County — 24th percentile — Below the median 1 of 12 flagged View by census tract →
Driven by Housing & Transportation, 65+ (well above); near the median on Health, Disability & Isolation ‡; below the median on Demographic Aging Pressure, Economic Precarity, 65+ and Social Isolation.
‡ theme includes at least one flagged input.
Beaverhead County — 20th percentile — Below the median 4 of 12 flagged View by census tract →
Near the median on Demographic Aging Pressure and Housing & Transportation, 65+ ‡; below the median on Economic Precarity, 65+, Health, Disability & Isolation ‡ and Social Isolation.
‡ theme includes at least one flagged input.
Lewis and Clark Coun — 20th percentile — Below the median 1 of 12 flagged View by census tract →
Driven by Health, Disability & Isolation ‡ (above) and Housing & Transportation, 65+ (above); below the median on Demographic Aging Pressure, Economic Precarity, 65+ and Social Isolation.
‡ theme includes at least one flagged input.
Well below the median — 11 counties (0th–20th percentile)
Roosevelt County — 18th percentile — Well below the median 4 of 12 flagged View by census tract →
Driven by Economic Precarity, 65+ (well above) and Social Isolation (well above); near the median on Health, Disability & Isolation ‡; below the median on Demographic Aging Pressure and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Jefferson County — 16th percentile — Well below the median 4 of 12 flagged View by census tract →
Driven by Health, Disability & Isolation ‡ (above) and Housing & Transportation, 65+ ‡ (above); below the median on Demographic Aging Pressure, Economic Precarity, 65+ and Social Isolation.
‡ theme includes at least one flagged input.
Dawson County — 15th percentile — Well below the median 5 of 12 flagged View by census tract →
Driven by Housing & Transportation, 65+ ‡ (above); below the median on Demographic Aging Pressure, Economic Precarity, 65+ ‡, Health, Disability & Isolation ‡ and Social Isolation.
‡ theme includes at least one flagged input.
Custer County — 13th percentile — Well below the median 1 of 12 flagged View by census tract →
Near the median on Economic Precarity, 65+ and Housing & Transportation, 65+ ‡; below the median on Demographic Aging Pressure, Health, Disability & Isolation and Social Isolation.
‡ theme includes at least one flagged input.
Judith Basin County — 11th percentile — Well below the median 2 of 12 flagged View by census tract →
Near the median on Demographic Aging Pressure and Economic Precarity, 65+; below the median on Health, Disability & Isolation ‡, Housing & Transportation, 65+ ‡ and Social Isolation.
‡ theme includes at least one flagged input.
Toole County — 9th percentile — Well below the median 4 of 12 flagged View by census tract →
Driven by Housing & Transportation, 65+ ‡ (well above); near the median on Economic Precarity, 65+ ‡; below the median on Demographic Aging Pressure, Health, Disability & Isolation ‡ and Social Isolation.
‡ theme includes at least one flagged input.
Missoula County — 7th percentile — Well below the median 1 of 12 flagged View by census tract →
Driven by Housing & Transportation, 65+ (well above); near the median on Economic Precarity, 65+ and Health, Disability & Isolation ‡; below the median on Demographic Aging Pressure and Social Isolation.
‡ theme includes at least one flagged input.
Powell County — 5th percentile — Well below the median 4 of 12 flagged View by census tract →
Near the median on Social Isolation; below the median on Demographic Aging Pressure, Economic Precarity, 65+ ‡, Health, Disability & Isolation ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Fallon County — 4th percentile — Well below the median 7 of 12 flagged View by census tract →
Below the median on Demographic Aging Pressure ‡, Economic Precarity, 65+ ‡, Health, Disability & Isolation ‡, Housing & Transportation, 65+ ‡ and Social Isolation ‡.
‡ theme includes at least one flagged input.
Richland County — 2nd percentile — Well below the median 3 of 12 flagged View by census tract →
Driven by Housing & Transportation, 65+ ‡ (above); below the median on Demographic Aging Pressure, Economic Precarity, 65+, Health, Disability & Isolation ‡ and Social Isolation.
‡ theme includes at least one flagged input.
Gallatin County — 0th percentile — Well below the median 1 of 12 flagged View by census tract →
Driven by Health, Disability & Isolation ‡ (above) and Housing & Transportation, 65+ (above); below the median on Demographic Aging Pressure, Economic Precarity, 65+ and Social Isolation.
‡ theme includes at least one flagged input.
AVI = a candidate Aging Vulnerability Index, computed by this platform from American Community Survey 2020–2024 5-year estimates, following the same method shape (percentile rank -> theme sum -> re-rank -> overall) as the CDC/ATSDR SVI this platform also recomputes — but AVI itself has no published ground truth to validate against. It is a first-cut, directional design. Percentiles rank each county against counties in MT.
Several of AVI's 12 input signals carry a documented high margin of error at this grain (most notably lack of health insurance, 65+) and are kept in the index with a flag rather than dropped, to preserve variable coverage. A county's flag count (shown per-county above) is a direct measure of how much its rank should be read as directional rather than precise.