Census data from 2010 through 2020, utilize CDC’s Vintage 2020 Postcensal Bridged Race Population Estimates. https://www.cdc.gov/nchs/nvss/bridged_race.htm. Estimates for each year beginning with 2010 are revised annually and will not match data previously released. These were discontinued with the 2020 release. Values for 1990, 2000, 2010, and 2020 represent revised population estimates for July 1, rather than actual census counts from April 1.

Census data for 2021 forward, will utilize Census Bureau’s proprietary Population Estimates and Projections with single year of age estimates provided to RFA from their Vintage 2021 estimates series*. These data are not public and are published here by special permission granted by the census bureau for the purposes of this project. The Census Bureau limits release of estimates by single year of age at the county level to a “by request only” basis due to concerns about the reliability of these estimates, especially when crossed by additional demographic characteristics. Users of the single-year-of-age county-level population estimates should carefully consider the limited reliability of these estimates.

* These estimates represent a tabulation from the “blended base” for April 1, 2020 which integrates the results of the 2020 Census, the 2020 Demographic Analysis estimates, and the Vintage 2020 estimates series. Therefore, there may be differences between these April 1, 2020 estimates and the results released from the 2020 Census. The Vintage 2021 population estimates methodology statement is located at this URL: https://www2.census.gov/programs-surveys/popest/technical-documentation/methodology/2020-2021/methods-statement-v2021.pdf

Census data from 2010 through 2020, utilize CDC’s Vintage 2020 Postcensal Bridged Race Population Estimates. https://www.cdc.gov/nchs/nvss/bridged_race.htm. Estimates for each year beginning with 2010 are revised annually and will not match data previously released. These were discontinued with the 2020 release. Values for 1990, 2000, 2010, and 2020 represent revised population estimates for July 1, rather than actual census counts from April 1.

Census data for 2021 forward, will utilize Census Bureau’s proprietary Population Estimates and Projections with single year of age estimates provided to RFA from their Vintage 2021 estimates series*. These data are not public and are published here by special permission granted by the census bureau for the purposes of this project. The Census Bureau limits release of estimates by single year of age at the county level to a “by request only” basis due to concerns about the reliability of these estimates, especially when crossed by additional demographic characteristics. Users of the single-year-of-age county-level population estimates should carefully consider the limited reliability of these estimates.

* These estimates represent a tabulation from the “blended base” for April 1, 2020 which integrates the results of the 2020 Census, the 2020 Demographic Analysis estimates, and the Vintage 2020 estimates series. Therefore, there may be differences between these April 1, 2020 estimates and the results released from the 2020 Census. The Vintage 2021 population estimates methodology statement is located at this URL: https://www2.census.gov/programs-surveys/popest/technical-documentation/methodology/2020-2021/methods-statement-v2021.pdf