Year	% (national estimate)
1960	17.95
1970	22.35
1978	33.72
1979	35.51
1980	31.54
1990	23.02
1991	34.542
1992	35.221
1993	35.942
1994	35.827
1995	37.284
1996	35.99
1997	36.704
1998	37.428
1999	36.466
2000	36.294
2001	34.635
2002	32.682
2003	32.633
2004	32.471
2005	34.323
2006	34.983
2007	35.09
2008	34.131
2009	33.381
2010	33.285
2011	33.31
2012	33.833
2013	33.089
2014	32.06
2015	31.646
2016	31.248
2017	30.832
2018	30.898
2019	32.402
2020	28.668
2021	32.518
2022	32.446
2023	33.67