Year	% (national estimate)
1979	53.91
1990	55.5
1991	83.65
1992	55.9
1993	57.4
1994	57.9
1995	56.3
1996	55.3
1997	57.1
1998	57.6
1999	58.7
2000	60.9
2001	82.42
2002	67
2003	73.6
2004	77.9
2005	77.66
2007	75.98
2009	79.55
2010	86.94
2011	86.01
2015	86.8