Year	% (national estimate)
1960	70.99
1970	61.25
1976	49.48
1979	57.21
1980	26.01
1981	58.06
1982	61.78
1984	62.51
1990	64.157
1991	61.094
1992	56.575
1993	54.63
1994	51.242
1995	51.111
1996	49.272
1997	52.218
1998	52.118
1999	65.105
2000	64.846
2001	64.433
2002	63.618
2003	61.908
2004	60.237
2005	60.314
2006	60.853
2007	52.847
2008	53.425
2009	49.816
2010	49.127
2011	50.677
2012	50.847
2013	50.71
2014	51.068
2015	51.225
2016	51.099
2017	51.893
2018	51.149
2019	53.307
2020	52.537
2021	53.128
2022	53.312
2023	52.893
