Year	% (national estimate)
1960	80.74
1970	72.99
1977	66.37
1978	65.24
1979	64.1
1980	67.99
1983	74.19
1985	72.6
1987	72.04
1989	71.07
1990	70.97
1991	59.33
1992	64.4
1993	63.6
1994	64.5
1995	63.15
1996	64.4
1997	61.3
1998	59
1999	57.7
2004	54.981
2005	53.665
2006	52.722
2007	52.5
2008	50.071
2009	50.662
2010	49.53
2011	49.628
2012	49.416
2013	48.982
2014	46.556
2017	46.713
2018	46.238
2019	45.685
2020	38.563
2021	42.298
2022	42.941
2023	43.626