Year	% (national estimate)
1961	61.85
1971	65.26
1976	68.866
1977	69.912
1978	70.768
1979	72.407
1980	73.148
1981	73.594
1982	70.74
1983	70.639
1984	70.818
1985	71.264
1986	72.309
1987	73.007
1988	73.068
1989	73.778
1990	72.404
1991	70.084
1992	67.786
1993	66.535
1994	65.898
1995	64.903
1996	64.043
1997	63.637
1998	63.435
1999	65.282
2000	65.837
2001	66.027
2002	67.743
2003	68.152
2004	67.585
2005	66.029
2006	67.081
2007	68.329
2008	68.58
2009	66.486
2010	65.273
2011	65.583
2012	64.615
2013	65.122
2014	64.965
2015	65.354
2016	64.385
2017	65.429
2018	65.131
2019	65.455
2020	62.46
2021	64.137
2022	64.544
2023	64.845