This is the latest Census estimate of each county's population, starting with the base population from either Census 2000 (for the July 1, 2000 estimates) or the revised population estimate for the most recent year (for the July 1 estimates for all years after 2000).
How Are These Numbers Estimated?
To arrive at the estimate the Census Bureau adds or subtracts the components of population change calculated for the time period. Basically, they add the estimated number of births and subtract the estimated number of deaths for the time period. Next, they add the estimates of net domestic migration, net foreign-born international migration, net movement to/from Puerto Rico, net Armed Forces movement to/from overseas, net native emigration from the United States, and the change in group quarters population.
The U. S. Census Bureau prepares annual estimates of total population for states, counties and all other units of general purpose government. Governmental units, including states, counties and units of local government may challenge the population estimates prepared by the Census Bureau under the provisions of Title 15, The Code of Federal Regulations (C.F.R.), Part 90.
