Year % (national estimate) 1972 36.91 1974 31.81 1976 30.4 1978 31.77 1979 30.56 1980 30.25 1981 30.01 1982 29.43 1983 32.78 1986 31.3 1987 30.15 1988 31.64 1989 31.72 1990 53.781 1991 55.182 1992 56.181 1993 60.194 1994 61.837 1995 61.688 1996 60.262 1997 59.216 1998 57.22 1999 57.023 2000 58.344 2001 57.432 2002 53.428 2003 53.596 2004 54.445 2005 55.77 2006 56.224 2007 55.573 2008 53.969 2009 52.739 2010 52.682 2011 50.435 2012 52.456 2013 52.51 2014 52.531 2015 51.761 2016 51.288 2017 51.118 2018 49.883 2019 48.69 2020 44.928 2021 45.747 2022 47.371