Population data is released by the Census Bureau's Population Estimates Program. Total population estimates for states, counties and incorporated places are released annually. Data series for births, deaths and domestic and international migration are used to update the decennial 2000 census base counts. These estimates are used in federal funding allocations, as denominators for vital rates and per capita time series, as survey controls and for monitoring recount demographic changes. With each new issue of the July 1 estimates, the Census Bureau reviews the estimates for each year back to the last census. Previously published estimates are superseded. The state data are released at the end of the calendar year. The county and sub-county population data are updated in late spring or early summer.