| State | 1970 | 1980 | 1990 | 2000 | 2010 |
|---|---|---|---|---|---|
| United States | 44.8 | 44.5 | 45.1 | 52.1 | 50.8 |
| Alabama | 32.4 | 36.6 | 37.3 | 44.2 | 43.1 |
| Alaska | 47 | 47.6 | 49.5 | 50.3 | 50.5 |
| Arizona | 44 | 42.9 | 43.8 | 48.8 | 44.2 |
| Arkansas | 30.9 | 37.8 | 38.1 | 45.8 | 43 |
| California | 47.3 | 44.3 | 43.6 | 50 | 50.4 |
| Colorado | 49.6 | 51.7 | 50.9 | 59.2 | 55.8 |
| Connecticut | 56.8 | 56 | 59 | 65 | 60.5 |
| Delaware | 47.8 | 47.5 | 51.4 | 54.3 | 51.3 |
| District of Columbia | 36.8 | 44.2 | 44.8 | 48.2 | 49.2 |
| Florida | 39.3 | 39 | 38.9 | 45.3 | 44.1 |
| Georgia | 38.2 | 39.9 | 42.1 | 48.4 | 44.9 |
| Hawaii | 57.7 | 56.6 | 59.4 | 58.1 | 58.8 |
| Idaho | 46.4 | 44.9 | 47.9 | 53.3 | 50.7 |
| Illinois | 47.5 | 42.9 | 44.4 | 53.6 | 53.9 |
| Indiana | 47.3 | 44.9 | 47.7 | 53.9 | 48.4 |
| Iowa | 50.7 | 52.1 | 52.8 | 59.1 | 58 |
| Kansas | 47.6 | 50.6 | 50.3 | 55.9 | 55.5 |
| Kentucky | 34.2 | 36.9 | 39.2 | 47.1 | 46.1 |
| Louisiana | 31.8 | 36.3 | 29.4 | 40.9 | 43 |
| Maine | 47.9 | 46.1 | 53.3 | 58.6 | 56.9 |
| Maryland | 47.2 | 48.4 | 53.6 | 59.5 | 60.5 |
| Massachusetts | 51.8 | 53.2 | 54.6 | 64.7 | 63.3 |
| Michigan | 46.4 | 42.3 | 42.8 | 54.1 | 46.2 |
| Minnesota | 53.2 | 55.7 | 57.8 | 63.4 | 62 |
| Mississippi | 29.1 | 33.8 | 34.5 | 40.8 | 39.3 |
| Missouri | 42 | 43.7 | 43.3 | 52.3 | 49.8 |
| Montana | 47 | 48.5 | 49.1 | 52.7 | 53 |
| Nebraska | 50 | 52.8 | 54.7 | 59.6 | 58.8 |
| Nevada | 45.4 | 43.7 | 46.3 | 47.5 | 35.1 |
| New Hampshire | 52.7 | 55 | 59.4 | 65.4 | 65.6 |
| New Jersey | 53.5 | 50.3 | 55.9 | 64.2 | 62.5 |
| New Mexico | 37.3 | 37.7 | 35.9 | 40.6 | 40.8 |
| New York | 44.8 | 40.5 | 43.7 | 51.2 | 55.1 |
| North Carolina | 38.3 | 43.1 | 45.3 | 50.5 | 47.3 |
| North Dakota | 47.9 | 52.2 | 54.6 | 59.8 | 60.2 |
| Ohio | 48.3 | 45.8 | 47.2 | 55.7 | 51.1 |
| Oklahoma | 41.1 | 45.9 | 41.8 | 48.1 | 46.7 |
| Oregon | 46.7 | 45.2 | 46.8 | 51.7 | 50.5 |
| Pennsylvania | 50 | 47.9 | 50.8 | 56.2 | 55.4 |
| Rhode Island | 50.5 | 49.1 | 52.2 | 58.5 | 55.4 |
| South Carolina | 37.3 | 40.3 | 38.9 | 42.7 | 41.7 |
| South Dakota | 46.5 | 46.3 | 51.1 | 55.4 | 54.2 |
| Tennessee | 36.8 | 39.6 | 39.7 | 43.2 | 43.6 |
| Texas | 39.9 | 44.8 | 39.5 | 46.9 | 47.8 |
| Utah | 52.5 | 51.8 | 53.5 | 59.9 | 55.4 |
| Vermont | 49.9 | 51.1 | 58.5 | 65.3 | 64.5 |
| Virginia | 44.7 | 51.3 | 54.2 | 60.7 | 59.6 |
| Washington | 49.6 | 49.7 | 50.9 | 54.9 | 53.3 |
| West Virginia | 35.3 | 38.6 | 39.1 | 44.3 | 44.5 |
| Wisconsin | 55 | 53.4 | 55.7 | 61.5 | 58.3 |
| Wyoming | 46.9 | 51.3 | 50.5 | 53.7 | 55.8 |
