Union coverage by year: (all)
| Year | Coverage |
|---|---|
| 1983 | 23.3 |
| 1984 | 21.6 |
| 1985 | 20.5 |
| 1986 | 19.9 |
| 1987 | 19.2 |
| 1988 | 19.0 |
| 1989 | 18.6 |
| 1990 | 18.3 |
| 1991 | 18.2 |
| 1992 | 17.9 |
| 1993 | 17.7 |
| 1994 | 17.5 |
| 1995 | 16.7 |
| 1996 | 16.2 |
| 1997 | 15.6 |
| 1998 | 15.4 |
| 1999 | 15.3 |
| 2000 | 14.9 |
| 2001 | 14.8 |
| 2002 | 14.6 |
| 2003 | 14.3 |
| 2004 | 13.8 |
| 2005 | 13.7 |
| 2006 | 13.2 |
| 2007 | 13.3 |
| 2008 | 13.7 |
| 2009 | 13.6 |
| 2010 | 13.1 |
Union coverage by state: 1983-2010
| State | Coverage |
|---|---|
| AK | 24.8 |
| AL | 13.7 |
| AR | 9.1 |
| AZ | 9.0 |
| CA | 20.0 |
| CO | 11.1 |
| CT | 18.9 |
| DC | 17.5 |
| DE | 15.4 |
| FL | 9.5 |
| GA | 8.6 |
| HI | 28.1 |
| IA | 16.1 |
| ID | 10.4 |
| IL | 20.8 |
| IN | 18.0 |
| KS | 12.3 |
| KY | 14.2 |
| LA | 9.5 |
| MA | 17.7 |
| MD | 17.2 |
| ME | 16.9 |
| MI | 24.7 |
| MN | 20.6 |
| MO | 15.9 |
| MS | 8.8 |
| MT | 17.7 |
| NC | 5.7 |
| ND | 11.3 |
| NE | 13.1 |
| NH | 12.2 |
| NJ | 23.6 |
| NM | 11.0 |
| NV | 20.2 |
| NY | 29.0 |
| OH | 20.4 |
| OK | 10.2 |
| OR | 20.1 |
| PA | 20.1 |
| RI | 19.4 |
| SC | 5.6 |
| SD | 9.5 |
| TN | 11.2 |
| TX | 7.9 |
| UT | 10.8 |
| VA | 8.9 |
| VT | 12.9 |
| WA | 24.1 |
| WI | 19.8 |
| WV | 18.7 |
| WY | 12.6 |
