Year % (national estimate) 1961 27.54 1972 21.33 1979 27.87 1980 28.1 1981 23.28 1982 28.7 1984 37.43 1986 43.12 1987 43.76 1989 42.71 1990 41.1 1991 37.73 1992 37.8 1993 29.97 1994 41.16 1995 44.6 1997 57.836 1998 56.451 1999 58.1 2000 57.302 2001 51.965 2002 74.387 2003 60.259 2004 62.755 2005 57.363 2006 59.884 2007 62.226 2008 63.528 2009 63.143 2010 64.221 2011 62.446 2012 61.995 2013 60.977 2014 58.849 2015 55.556 2016 56.013 2017 57.86 2018 57.777 2019 57.793 2020 50.308 2021 54.203 2022 55.674 2023 52.817