The population for the demographic variables (County/State, Year, Age, Sex and Race/Ethnicity) as specified in the corresponding row.
In non-census years race/ethnicity population data are only available for a few counties (see Race/Ethnicity help for more details)
Source: Census years (1990, 2000, and 2010) are obtained from the U.S. Census Bureau. Non-census years (e.g., 1991, 1992, 2011, 2012, etc.) are obtained from the Pennsylvania State Data Center.