Year	% (national estimate)
1960	26.98
1970	35.1
1979	33.05
1980	26.47
1983	28.14
1984	28.95
1985	29.7
1986	30.14
1988	30.94
1989	32.59
1990	26.46
1991	33.41
1993	35.54
1994	35.25
1995	34.88
1996	32.1
1997	35.72
1998	36.13
1999	36.69
2000	34.1
2002	34.71
2003	35.87
2004	34.88
2005	35.54
2006	33.5
2007	32.82
2008	33.38
2009	34.33
2010	31.941
2011	28.895
2012	31.512
2013	33.832
2014	32.425
2015	30.728
2016	31.468
2017	33.121
2018	33.758
2019	35.697
2020	43.474
2021	28.82
2022	33.351
2023	33.517