Year	% (national estimate)
1961	75.39
1966	72.21
1971	67.12
1981	62.83
1983	64.308
1984	66.208
1985	69.591
1986	69.767
1987	70.764
1988	71.123
1989	72.649
1990	71.788
1991	70.12
1992	67.896
1993	66.007
1994	64.628
1995	63.654
1996	64.389
1997	64.309
1998	63.848
1999	63.005
2000	63.407
2001	61.89
2002	62.386
2003	61.179
2004	61.56
2005	61.244
2006	61.306
2007	60.494
2008	60.231
2009	58.141
2010	57.362
2011	57.223
2012	57.719
2013	56.921
2014	56.928
2015	57.731
2016	57.147
2017	56.588
2018	56.286
2019	54.69
2020	54.665
2021	51.215
2022	54.351
2023	53.654