Year % (national estimate) 1960 66.5 1970 65.26 1980 63.36 1990 66.6 1991 66.909 1992 66.231 1993 68.933 1994 64.753 1995 61.851 1996 64.516 1997 64.817 1998 63.527 1999 69.337 2000 65.979 2001 66.885 2002 68.098 2003 68.265 2004 65.952 2005 64.704 2006 67.032 2007 64.468 2008 66.126 2009 68.485 2010 67.384 2011 67.895 2012 66.235 2013 67.069 2014 67.454 2015 68.314 2016 68.961 2017 67.762 2018 67.625 2019 66.307 2020 64.571 2021 64.178 2022 63.387 2023 64.427