Year	% (national estimate)
1979	32.32
1989	45.19
1991	64.6
1992	63.3
1993	65.8
1994	67.13
1995	65.8
1996	65.2
1997	67.6
1998	65.21
1999	69.4
2001	70.9
2002	69.4
2004	67.96
2008	69.7
2009	62.94
2011	62.1
2012	64.05