Year	% (national estimate)
1978	48.72
1979	49.14
1980	50.14
1985	51.34
1986	52.18
1988	54.07
1989	55.09
1990	56.22
1991	63.684
1992	63.223
1993	62.749
1994	61.826
1995	62.183
1996	65.011
1997	64.582
1998	65.545
1999	65.726
2000	65.57
2001	66.113
2002	65.74
2003	65.053
2004	64.37
2005	64.005
2006	64.661
2007	65.16
2008	65.903
2009	65.429
2010	63.778
2011	64.481
2012	64.491
2013	64.331
2014	64.632
2015	64.876
2016	65.197
2017	65.161
2018	65.256
2019	65.233
2020	64.597
2021	63.942
2022	63.775
2023	64.834