Year	% (national estimate)
1960	47.89
1970	47.11
1978	52.25
1983	50.07
1985	49.46
1987	52.33
1988	51.44
1989	49.4
1990	50.01
1991	49.94
1992	50.39
1993	49.74
1994	49.06
1995	50.08
1996	50.16
1997	48.56
1998	50.02
1999	49.11
2000	47.28
2001	44.48
2002	49.08
2003	43.054
2004	43.769
2005	43.384
2006	42.758
2007	41.971
2008	41.471
2009	41.844
2010	41.432
2011	43.142
2012	42.626
2013	41.831
2014	42.556
2015	40.46
2016	39.972
2017	37.104
2018	35.701
2019	34.754
2020	30.126
2021	31.171
2022	32.539