Year % (national estimate) 1972 37.86 1974 32.39 1976 31.2 1978 32.46 1979 31.07 1980 31.21 1981 31.55 1982 31.15 1983 34.1 1986 33.18 1987 31.34 1988 33.62 1989 32.81 1990 61.647 1991 63.88 1992 63.771 1993 68.939 1994 68.908 1995 68.089 1996 65.87 1997 65.082 1998 63.149 1999 61.428 2000 62.042 2001 60.649 2002 56.472 2003 55.341 2004 56.304 2005 57.885 2006 58.418 2007 58.392 2008 57.08 2009 54.398 2010 54.489 2011 52.549 2012 54.964 2013 55.541 2014 55.251 2015 54.277 2016 53.278 2017 52.822 2018 50.98 2019 49.2 2020 45.157 2021 45.893 2022 47.506