Year	% (national estimate)
1974	46.63
1976	46.34
1978	47.91
1979	47.81
1980	47.16
1981	47.26
1982	47.09
1983	47.61
1984	47.26
1985	45.91
1986	47.05
1987	47.39
1988	48.1
1989	47.39
1990	51.938
1991	51.565
1992	51.63
1993	53.511
1994	55.731
1995	56.749
1996	56.34
1997	55.331
1998	54.254
1999	54.377
2000	54.877
2001	54.52
2002	53.243
2003	53.2
2004	53.923
2005	55.229
2006	55.897
2007	57.127
2008	58.11
2009	57.201
2010	58.054
2011	58.589
2012	60.848
2013	61.115
2014	61.821
2015	62.158
2016	62.535
2017	62.78
2018	62.869
2019	62.571
2020	60.763
2021	60.272
2022	62.346
