Year % (national estimate) 1977 42.8 1979 53.61 1980 44.01 1981 54.96 1982 67.49 1984 55.93 1985 56.86 1986 56.3 1987 55.91 1988 55.98 1989 57.31 1990 63.066 1991 60.293 1992 56.152 1993 52.443 1994 51.473 1995 47.173 1996 46.106 1997 46.534 1998 47.64 1999 50.894 2000 51.318 2001 52.23 2002 52.742 2003 52.492 2004 51.69 2005 52.534 2006 53.052 2007 53.25 2008 53.548 2009 52.642 2010 51.743 2011 51.846 2012 52.04 2013 51.361 2014 51.062 2015 50.697 2016 50.296 2017 50.581 2018 51.801 2019 52.343 2020 51.123 2021 52.684 2022 54.464 2023 54.752