Year	% (national estimate)
1992	46.58
1993	46.86
1994	47.09
1995	47.62
1997	52.53
1998	51.82
2000	54.05
2003	51.51
2004	52.93
2005	54.56
2006	56.42
2007	59.52
2008	61.94
2009	64.51
2010	64.71
2011	66.01
2012	65.66
2013	66.57
2014	67.19
2015	66.96
2016	66.33