Year	% (national estimate)
1970	29.16
1979	33.59
1980	29.18
1981	33.61
1983	36.37
1985	37.36
1986	37.97
1987	33.82
1988	36.08
1989	33.73
1990	36.38
1991	39.98
1993	38
1995	40.22
1996	42.45
1997	38.8
1998	40.98
1999	40.37
2000	41.6
2002	41.49
2005	45.13
2006	47.9
2007	45.24
2008	44.34
2009	41.41
2010	37.741
2011	35.082
2012	37.423
2013	38.027
2014	37.112
2015	35.905
2016	35.44
2019	31.063
2020	27.67
2021	31.536
2022	31.432