Year	% (national estimate)
1960	18.29
1992	46.73
1993	52.38
1994	54.74
1995	50.63
1996	57.98
1997	47.99
1998	44.44
2000	47.78
2001	47.46
2002	41.12
2003	33.08
2004	33.5
2005	37.72
2006	39.18
2007	45.03
2008	47.22
2009	54.84
2010	52.6
2011	53.15
2012	49.75
2013	51.7
2014	50.71
2015	49.21
2016	45.85