Year % (national estimate) 1976 25.935860058309036 1980 26.34347130116625 1981 26.695842450765866 1982 27.189481098849495 1985 28.239122574424492 1986 28.27044399476253 1987 28.285680668313915 1989 70.1501976284585 1990 61.79062483410309 1991 65.12698412698413 1992 62.065161828405394 1993 68.57142857142857 1994 69.375 1995 69.6334388185654 1996 75.94765951706461 1997 72.61239368165249 1999 74.12738220719902 2000 72.49179131703757 2001 79.31488801054019 2002 74.0119760479042 2003 76.71068427370949 2004 76.71068427370949 2005 75.36239103362391 2006 77.3024238597173 2007 77.2300053200922 2008 76.01212726320787 2009 76.70818440218122 2011 75.39692173237522 2012 72.46575684239414 2013 73.66566212547632 2014 75.00702049985959 2015 68.65567041273496 2016 73.22138187411869 2017 75.68174281268335 2018 79.44726058960532 2019 80.73729132977493 2020 74.10242708190935 2021 84.03568604774661 2022 84.4963246104087