Year	% (national estimate)
1976	74.79
1977	74.98
1978	74.84
1979	74.84
1980	74.85
1981	76.69
1982	76.59
1983	75.06
1984	75.09
1985	75.56
1986	74.16
1988	71.38
1989	28.3
1990	71.37
1991	68.68
1992	68.66
1993	65.95
1994	65.35
1995	65.26
1997	66.01
1998	65.18
2000	69.34
2002	70.18
2004	70.45
2005	60.291
2006	66.804
2007	64.832
2008	62.891
2009	62.144
2010	62.087
2011	60.566
2012	60.63
2013	61.893
2014	59.704
2015	59.761
2016	59.341
2018	61.291
2019	59.345
2021	64.663