Year	% (national estimate)
1961	49.72
1971	31.99
1981	29.53
1982	28.43
1983	36.21
1984	34.641
1985	34.017
1986	33.327
1987	32.992
1988	34.515
1989	35.209
1990	35.288
1991	33.927
1992	34.892
1993	34.759
1994	33.568
1995	34.074
1996	35.414
1997	33.853
1998	38.727
1999	37.457
2000	35.923
2001	33.627
2002	33.116
2003	30.905
2004	33.205
2005	30.285
2006	28.317
2007	27.273
2008	25.814
2009	27.244
2010	26.973
2011	26.583
2012	27.181
2013	25.432
2014	25.977
2015	24.038
2016	22.743
2017	23.86
2018	21.18
2019	21.002
2020	19.091
2021	18.783
2022	21.447
2023	23.1