Year	% (national estimate)
1960	28.26
1970	32.76
1978	42.07
1983	40.94
1985	37.91
1987	40.32
1988	38.26
1989	37.79
1990	38.78
1991	38.31
1992	39.46
1993	38.59
1994	37.15
1995	38.38
1996	37.98
1997	35.92
1998	37.13
1999	36.84
2000	36.34
2001	34.537
2002	38.25
2003	32.976
2004	32.941
2005	33.468
2006	33.084
2007	32.378
2008	31.607
2009	32.25
2010	32.074
2011	33.252
2012	32.801
2013	31.993
2014	32.782
2015	31.358
2016	30.292
2017	27.5
2018	27.193
2019	26.99
2020	23.265
2021	23.627
2022	25.176