Year	% (national estimate)
1963	51.23
1971	42.45
1977	47.01
1989	47.55
1990	48.76
1991	49.17
1995	48.16
1996	48.68
1998	49.5
1999	59.51
2000	50
2001	50.672
2006	47.74
2012	70.401
2014	51.663