The U.S. Census Bureau today released July 1, 2009, population estimates for each of the nation's counties and metropolitan and micropolitan statistical areas.
The estimates are based on 2000 Census data and updated by using administrative records to estimate components of population change — namely births, deaths, and domestic and international migration. Provided are annual county and metro area estimates for the 2000 to 2009 period, as well as rankings by population size in 2009 and by numeric and percent change from 2000 to 2009 and 2008 to 2009.
The new estimates are not 2010 Census population counts. They are, however, the last estimates to use 2000 Census results as a base.
The 2011 population estimates will be the first in the estimates series to be based on the 2010 Census population counts. Communities can use the Take 10 challenge program to follow in real time their county's participation rate in the 2010 Census. The Census Bureau is encouraging every household to fill out and return their census form to help ensure the most complete and accurate census.
"These are the last population estimates for counties and metro areas before the release of 2010 Census numbers for smaller areas in April 2011," Census Bureau Director Robert Groves said. "In December, we will release the official population counts for the nation and states."
The 2010 Census population totals will be used to apportion seats in the U.S. House of Representatives. By April 1, 2011, the Census Bureau must release data for counties, cities and other small geographic areas so that states can proceed with redistricting.
"Census numbers govern the distribution of more than $400 billion in federal funds each year and serve as the baseline for future post-census population estimates," Groves said. "It is critical that every U.S. household complete and mail back their questionnaire so that our counts are as accurate as possible."
Also released today were the estimates for all of Puerto Rico's municipios.
All geographic boundaries for the July 1, 2009, population estimates series are defined as of Jan. 1, 2009. The Office of Management and Budget’s statistical area definitions (for metropolitan and micropolitan statistical areas) are those issued by that agency in November 2008. Metro areas contain at least one urbanized area of 50,000 or more population and micro areas contain at least one urban cluster of at least 10,000 (but less than 50,000) population. Both metro and micro areas consist of one or more whole counties or county equivalents.