Year % (national estimate) 1960 50.61 1975 60.03 1976 59.99 1977 59.98 1979 69.44 1981 69.23 1982 69.07 1983 68.88 1991 58.811 1992 60.215 1993 59.731 1994 59.058 1995 68.492 1996 63.468 1997 67.448 1998 74.229 1999 74.85 2000 80.458 2001 79.496 2002 70.366 2003 76.266 2004 75.651 2005 78.065 2006 80.31 2007 79.511 2008 79.447 2009 75.481 2010 76.089 2011 74.57 2012 78.039 2013 81.46 2014 78.752 2015 81.988 2016 83.468 2017 82.391 2018 80.978 2019 80.614 2020 75.434 2021 76.439 2022 79.129 2023 81.723