| Year | Bachelor’s degree | Post-graduate degree |
|---|---|---|
| 1960 | 2.5 | 2.6 |
| 1970 | 4.0 | 5.0 |
| 1980 | 7.0 | 8.7 |
| 1990 | 11.5 | 8.8 |
| 2000 | 13.7 | 10.3 |
| 2010 | 15.9 | 11.1 |
| 2013 | 16.4 | 11.9 |
| 2014 | 16.6 | 12.0 |
Source: Pew Research Center tabulations of 1960-2000 decennial censuses and 2010, 2013 and 2014 American Community Surveys (IPUMS)
