Year % (national estimate) 1960 56.28 1977 45.39 1979 45.31 1980 48.41 1981 47.97 1982 48.97 1983 48.51 1985 47.513 1986 49.06 1987 58.596 1988 56.142 1989 57.237 1990 59.225 1991 60.118 1992 61.141 1993 59.73 1994 59.609 1995 61.81 1996 60.93 1997 61.781 1998 64.916 1999 68.05 2000 70.883 2001 72.445 2002 72.74 2003 73.077 2004 71.757 2005 66.443 2006 66.264 2007 68.515 2008 69.169 2009 69.577 2010 68.609 2011 69.231 2012 70.753 2013 70.023 2014 67.7 2015 69.417 2016 69.203 2017 69.693 2018 69.787 2019 70.317 2020 69.859 2021 81.361 2022 81.832 2023 82.989