Year % (national estimate) 1962 49.42 1968 56 1975 48.48 1979 52.47 1980 52.28 1981 50.91 1982 51.35 1983 57.871 1984 55.82 1985 55.281 1986 54.98 1987 53.045 1988 49.387 1989 47.984 1990 47.737 1991 42.117 1992 41.936 1993 39.966 1994 38.406 1995 37.29 1996 37.385 1997 36.41 1998 36.275 1999 39.501 2000 38.593 2001 39.225 2002 41.018 2003 40.68 2004 40.116 2005 37.577 2006 37.829 2007 37.774 2008 38.361 2009 38.851 2010 38.326 2011 37.086 2012 36.477 2013 38.821 2014 37.731 2015 37.976 2016 37.765 2017 38.354 2018 39.22 2019 37.8 2020 36.483 2021 39.987 2022 42.771 2023 44.903