As of July 2004, 21 states, the District of Columbia and Puerto Rico have primary safety belt laws.
Below is the list with current seat belt use rates vs. rate when the state passed primary belt.

Year Passed                Use Rate Year Passed                                         2004 Rate

Alabama                    1999                                                    58%                                                                        80%

California                   1993                                         high 60's low 70's                                                            90.4%

Connecticut              1986                                                    11.5%                                                                     82.9%

Delaware                    2003                                                    75%                                                                        82.3%

D.C                             1997                                                    78%                                                                        87%

Georgia                      1996                                                    57.8%                                                                     86.7%

Hawaii                        1985                                    No survey but high 60's low 70's                                       95.1%

Illinois                        2003                                                    76.2%                                                                     83%

Indiana                       1998                                                    61.8%                                                                     83.4%

Iowa                           1986                                                    43%                                                                        86.4%

Louisiana                   1995                                                    50%                                                                        75%

Maryland                   1997                                                    70%                                                                        89%

Michigan                  2000                                                    70.1%                                                                     90.5%

New Jersey                1999                                                    63.3%                                                                     82%

New Mexico             1986                                                    27%                                                                        89.7%

New York                   1984                                                    16%                                                                        85%

North Carolina          1985                                                    25.5%                                                                     86.1%

Oklahoma                  1997                                                    47.4%                                                                     80.3%

Oregon                       1990                                                    50%                                                                        92.6%

Tennessee                 2004                                                                                                                                    72%

Texas                         1985                                                    9.6%                                                                       83.2%

Washington             2002                                                    83%                                                                        94.2%

Puerto Rico               1975                                                    5%                                                                          90.1%.