Year % (national estimate) 1991 70.791 1992 70.606 1993 70.313 1994 70.771 1995 73.612 1996 73.133 1997 71.555 1998 73.069 1999 76.091 2000 77.674 2001 76.712 2002 76.183 2003 75.61 2004 74.695 2005 75.159 2006 75.375 2007 75.984 2008 75.019 2009 72.06 2010 71.609 2011 71.651 2012 72.712 2013 73.699 2014 74.892 2015 76.439 2016 77.318 2017 76.754 2018 75.941 2019 74.966 2020 71.03 2021 64.882 2022 68.305 2023 68.273