Year	% (national estimate)
1962	47.19
1968	45.94
1975	43.64
1979	42.55
1980	41.62
1981	41.14
1982	41.02
1983	49.035
1984	48.463
1985	47.837
1986	47.882
1987	46.405
1988	43.672
1989	42.726
1990	41.574
1991	37.824
1992	37.164
1993	36.196
1994	34.471
1995	33.794
1996	32.664
1997	31.514
1998	31.688
1999	32.212
2000	32.386
2001	32.251
2002	32.699
2003	33.601
2004	33.274
2005	30.485
2006	30.388
2007	31.447
2008	31.034
2009	32.288
2010	31.666
2011	30.835
2012	30.221
2013	31.757
2014	30.954
2015	31.745
2016	32.004
2017	31.516
2018	32.042
2019	31.895
2020	31.17
2021	35.893
2022	37.831
2023	40.031