Year	% (national estimate)
1977	47.7
1979	60.74
1980	49.28
1981	61.84
1982	65.58
1984	61.94
1985	62.38
1986	61.95
1987	61.61
1988	61.62
1989	63.26
1990	67.585
1991	63.805
1992	59.022
1993	55.22
1994	54.377
1995	50.715
1996	50.115
1997	51.137
1998	52.303
1999	55.606
2000	56.176
2001	56.773
2002	56.63
2003	56.251
2004	55.672
2005	56.251
2006	56.778
2007	57.008
2008	57.563
2009	55.501
2010	54.897
2011	55.262
2012	55.135
2013	54.296
2014	53.801
2015	53.43
2016	53.439
2017	53.77
2018	55.051
2019	55.376
2020	54.41
2021	55.811
2022	57.021
2023	56.736