Population Characteristics - Age (1) To resort data: click column headings. To download data: click here. County Name Under 18 Rank Under 18 18 - 64 65 and over Dependency ratio Source: 1980: U.S. Bureau of the Census, (https://www.census.gov/programs-surveys/decennial-census/data.html); 1990, 2000, and 2010: U.S. Bureau of the Census, Census of Population and Housing, (https://data.census.gov/cedsci/); 2011-2021: U.S. Bureau of the Census, County Population Estimates, (https://www.census.gov/popest/); DATE LAST UPDATED: May 10, 2023.