Year	% (national estimate)
1960	52.44
1966	53.22
1970	54.27
1981	57.67
1983	57.706
1984	55.38
1985	58.066
1986	56.366
1987	54.134
1988	51.371
1989	50.507
1990	43.767
1991	49.976
1992	50.349
1993	45.507
1994	45.036
1995	39.958
1996	38.501
1997	35.315
1998	33.356
1999	31.867
2000	30.562
2001	32.06
2002	31.176
2003	29.676
2004	26.397
2005	25.472
2006	25.007
2007	22.314
2008	27.123
2009	30.731
2010	23.994
2011	24.212
2012	24.872
2013	21.623
2014	25.42
2015	34.625
2016	31.373
2017	28.53
2018	32.282
2019	31.33
2020	30.955
2021	35.266
2022	35.011
2023	33.351