Year % (national estimate) 1976 59.889 1977 59.76 1978 60.408 1979 63.053 1980 63.357 1981 63.505 1982 56.129 1983 55.25 1984 57.291 1985 58.907 1986 60.74 1987 62.536 1988 64.008 1989 64.791 1990 62.603 1991 57.096 1992 54.41 1993 53.435 1994 54.101 1995 54.3 1996 53.234 1997 52.737 1998 52.938 1999 55.293 2000 56.724 2001 56.453 2002 57.318 2003 57.695 2004 57.469 2005 56.712 2006 58.45 2007 60.025 2008 59.749 2009 54.545 2010 54.195 2011 55.261 2012 54.432 2013 55.469 2014 55.31 2015 55.792 2016 55.107 2017 57.06 2018 57.357 2019 57.558 2020 49.506 2021 54.844 2022 57.329 2023 57.381