Year	% (national estimate)
1975	31.56
1977	51.46
1979	52.03
1981	57.68
1982	57.29
1983	55.6
1984	48.25
1985	49.08
1986	49.57
1987	50.72
1988	52.56
1989	51.68
1994	53.54
1996	55.1
1998	58.2
2002	57.98
2005	57.422
2006	59.278
2007	59.727
2008	60.279
2009	60.137
2010	59.312
2011	59.234
2012	58.948
2016	57.93
2017	63.056
2020	55.38