Year	% (national estimate)
1976	72.688
1977	71.851
1978	71.976
1979	73.05
1980	72.842
1981	72.826
1982	68.381
1983	67.376
1984	67.975
1985	68.707
1986	69.574
1987	70.295
1988	70.934
1989	71.104
1990	69.905
1991	66.921
1992	64.984
1993	64.554
1994	65.141
1995	65.362
1996	65.027
1997	65.546
1998	65.975
1999	66.72
2000	67.324
2001	66.825
2002	67.075
2003	67.588
2004	67.696
2005	67.696
2006	67.78
2007	68.013
2008	67.992
2009	65.33
2010	65.461
2011	66.033
2012	66.036
2013	66.07
2014	65.734
2015	65.684
2016	65.153
2017	65.82
2018	65.985
2019	66.231
2020	62.202
2021	64.463
2022	65.738
2023	65.813