Year	% (national estimate)
1970	50.19
1979	53.21
1980	46.83
1981	53.62
1983	55.48
1985	55.58
1986	54.53
1987	47.95
1988	52.19
1989	49.27
1990	50.22
1991	51.51
1993	48.88
1995	51.22
1996	52.06
1997	49.9
1998	51.22
1999	51.15
2000	51.68
2002	49.65
2005	53.82
2006	54.44
2007	53.74
2008	52.13
2009	50.45
2010	46.431
2011	44.892
2012	45.272
2013	45.247
2014	44.288
2015	43.605
2016	41.542
2019	38.652
2020	34.788
2021	36.583
2022	35.248