Marion County Population - Illinois

Data Item State County
Population, 2019 estimate - (Number)
Year Value
200041,687
200141,365
200240,893
200340,454
200440,035
200539,688
200639,736
200739,584
200839,422
200939,008
201039,416
201139,141
201239,008
201338,669
201438,555
201538,359
201638,045
201737,726
201837,381
201937,205

Sources: U.S. Census Bureau, Population Estimates Program (PEP), updated annually. Population and Housing Unit Estimates

Definitions:

The Census Bureau's Population Estimates Program (PEP) produces estimates of the population for the United States, its states, counties, cities, and towns, as well as for the Commonwealth of Puerto Rico and its municipios (county-equivalents for Puerto Rico). Additionally, housing unit estimates are produced for the nation, states, and counties. The timing of the release of estimates varies according to the level of geography. See the Schedule of Releases for more information.

Resident Population - All persons who are "usually resident" in a specified geographic area. For the United States, the resident population includes all persons who usually reside in the 50 states and the District of Columbia, but excludes residents of the Commonwealth of Puerto Rico and the Island areas under U.S. sovereignty or jurisdiction (principally American Samoa, Guam, United States Virgin Islands, and the Commonwealth of the Northern Mariana Islands). In addition, the U.S. resident population excludes U.S. Armed Forces overseas and civilian U.S. citizens whose usual place of residence is outside the United States.

Estimates Base - The population count or estimate used as the starting point in the estimates process. It can be the most recent updated Census count or the estimate for a previous date within the same vintage. (The vintage year (e.g., V2019) refers to the final year of the time series). The April 1, 2010 Population Estimates base reflects changes to the 2010 Census population from the Boundary and Annexation Survey (BAS) and other geographic program revisions. It may reflect changes from the Count Question Resolution program. Click on the "Scope and Methodology" link for details for each vintage year.

Population percent change - The difference between the population of an area at the beginning and end of a time period, expressed as a percentage of the beginning population.

Methodology for U.S. and Puerto Rico