| Less than high school graduate | High school graduate | High school or less | Some college | College graduate | |
|---|---|---|---|---|---|
| 2000 | 19% | 40% | 67% | 78% | |
| 2001 | 21% | 43% | 68% | 81% | |
| 2002 | 24% | 48% | 73% | 83% | |
| 2003 | 25% | 51% | 75% | 85% | |
| 2004 | 27% | 53% | 76% | 86% | |
| 2005 | 32% | 58% | 80% | 89% | |
| 2006 | 37% | 61% | 83% | 91% | |
| 2007 | 40% | 65% | 85% | 92% | |
| 2008 | 38% | 65% | 86% | 93% | |
| 2009 | 40% | 68% | 87% | 94% | |
| 2010 | 41% | 68% | 87% | 93% | |
| 2011 | 43% | 72% | 89% | 94% | |
| 2012 | 52% | 75% | 91% | 96% | |
| 2013 | 54% | 75% | 92% | 96% | |
| 2014 | 55% | 76% | 91% | 96% | |
| 2015 | 62% | 78% | 92% | 96% | |
| 2016 | 68% | 81% | 94% | 98% | |
| 2018 | 65% | 84% | 93% | 97% | |
| 2019 | 71% | 84% | 95% | 98% | |
| 2021 | 86% | 97% | 98% |
