| 1990 - 2000 Population Percent Change Persons Age 65 and Older | ||||
| Pennsylvania Counties | ||||
| 1990 | 2000 | Percent | ||
| Name | Population | Population | Change | |
| Pennsylvania | 1,829,106 | 1,919,165 | 4.9 | |
| Adams County | 10,634 | 12,656 | 19.0 | |
| Allegheny County | 231,911 | 228,416 | -1.5 | |
| Armstrong County | 12,887 | 13,053 | 1.3 | |
| Beaver County | 31,520 | 33,424 | 6.0 | |
| Bedford County | 7,347 | 8,243 | 12.2 | |
| Berks County | 52,526 | 56,190 | 7.0 | |
| Blair County | 22,154 | 22,456 | 1.4 | |
| Bradford County | 8,940 | 9,865 | 10.3 | |
| Bucks County | 58,912 | 74,094 | 25.8 | |
| Butler County | 20,481 | 24,821 | 21.2 | |
| Cambria County | 30,582 | 30,087 | -1.6 | |
| Cameron County | 1,095 | 1,180 | 7.8 | |
| Carbon County | 10,481 | 10,866 | 3.7 | |
| Centre County | 11,109 | 14,077 | 26.7 | |
| Chester County | 40,977 | 50,677 | 23.7 | |
| Clarion County | 5,793 | 6,336 | 9.4 | |
| Clearfield County | 12,987 | 14,094 | 8.5 | |
| Clinton County | 5,944 | 6,363 | 7.0 | |
| Columbia County | 9,974 | 10,202 | 2.3 | |
| Crawford County | 13,301 | 14,052 | 5.6 | |
| Cumberland County | 26,141 | 31,754 | 21.5 | |
| Dauphin County | 34,012 | 35,844 | 5.4 | |
| Delaware County | 84,932 | 85,669 | 0.9 | |
| Elk County | 5,576 | 6,073 | 8.9 | |
| Erie County | 38,025 | 40,256 | 5.9 | |
| Fayette County | 26,076 | 26,930 | 3.3 | |
| Forest County | 970 | 985 | 1.5 | |
| Franklin County | 17,498 | 20,751 | 18.6 | |
| Fulton County | 1,796 | 2,068 | 15.1 | |
| Greene County | 6,501 | 6,193 | -4.7 | |
| Huntingdon County | 5,951 | 6,748 | 13.4 | |
| Indiana County | 12,407 | 13,323 | 7.4 | |
| Jefferson County | 7,944 | 8,226 | 3.5 | |
| Juniata County | 2,987 | 3,471 | 16.2 | |
| Lackawanna County | 43,193 | 41,542 | -3.8 | |
| Lancaster County | 55,469 | 66,060 | 19.1 | |
| Lawrence County | 17,783 | 18,223 | 2.5 | |
| Lebanon County | 17,070 | 19,696 | 15.4 | |
| Lehigh County | 44,865 | 49,434 | 10.2 | |
| Luzerne County | 64,717 | 62,740 | -3.1 | |
| Lycoming County | 17,940 | 19,251 | 7.3 | |
| McKean County | 7,882 | 7,663 | -2.8 | |
| Mercer County | 20,777 | 21,740 | 4.6 | |
| Mifflin County | 7,383 | 7,907 | 7.1 | |
| Monroe County | 12,499 | 17,036 | 36.3 | |
| Montgomery County | 101,993 | 111,797 | 9.6 | |
| Montour County | 2,926 | 3,120 | 6.6 | |
| Northampton County | 37,019 | 42,030 | 13.5 | |
| Northumberland County | 18,287 | 18,002 | -1.6 | |
| Perry County | 4,569 | 5,345 | 17.0 | |
| Philadelphia County | 240,714 | 213,722 | -11.2 | |
| Pike County | 4,357 | 7,017 | 61.1 | |
| Potter County | 2,754 | 3,014 | 9.4 | |
| Schuylkill County | 30,549 | 29,866 | -2.2 | |
| Snyder County | 4,616 | 5,275 | 14.3 | |
| Somerset County | 13,252 | 14,436 | 8.9 | |
| Sullivan County | 1,275 | 1,434 | 12.5 | |
| Susquehanna County | 6,185 | 6,546 | 5.8 | |
| Tioga County | 6,151 | 6,608 | 7.4 | |
| Union County | 4,548 | 5,584 | 22.8 | |
| Venango County | 8,921 | 9,657 | 8.3 | |
| Warren County | 7,053 | 7,312 | 3.7 | |
| Washington County | 35,770 | 36,323 | 1.5 | |
| Wayne County | 6,766 | 8,352 | 23.4 | |
| Westmoreland County | 63,472 | 67,781 | 6.8 | |
| Wyoming County | 3,537 | 3,717 | 5.1 | |
| York County | 44,443 | 51,492 | 15.9 | |