Year % (national estimate) 1961 58.16 1966 60.71 1971 55.31 1976 57.34 1979 63.847 1980 66.176 1981 65.516 1982 65.375 1983 65.872 1984 66.167 1985 66.755 1986 67.982 1987 67.674 1988 67.322 1989 68.711 1990 68.855 1991 66.687 1992 66.484 1993 65.721 1994 68.142 1995 69.555 1996 69.481 1997 67.519 1998 67.606 1999 67.967 2000 68.454 2001 69.064 2002 68.223 2003 69.008 2004 69.073 2005 69.566 2006 69.486 2007 69.689 2008 69.471 2009 67.729 2010 67.19 2011 67.468 2012 66.778 2013 66.258 2014 66.237 2015 66.706 2016 66.358 2017 66.353 2018 67.542 2019 67.963 2020 66.527 2021 69.021 2022 72.559 2023 71.018