Year	% (national estimate)
1960	57.69
1970	64.49
1978	69.95
1979	70.99
1980	71.29
1981	71.52
1982	70.42
1984	62.29
1985	61.05
1986	61.3
1987	61.487
1988	60.57
1989	59.467
1990	58.416
1991	56.594
1992	50.951
1993	47.5
1994	45.228
1995	43.136
1996	42.312
1997	44.161
1998	47.086
1999	46.332
2000	44.788
2001	46.548
2002	47.115
2003	44.852
2004	42.637
2005	42.119
2006	41.653
2007	41.329
2008	40.891
2009	38.697
2010	36.119
2011	38.151
2012	37.076
2013	35.002
2014	34.303
2015	33.527
2016	33.167
2017	33.984
2018	34.18
2019	34.279
2020	30.332
2021	29.74
2022	31.091
2023	35.339