Year	% (national estimate)
1974	49.11
1976	49.69
1977	50.34
1978	52
1979	50.86
1981	50.89
1983	52.174
1984	53.277
1985	53.999
1986	56.058
1987	56.054
1988	56.329
1989	55.157
1990	55.978
1991	55.52
1992	56.237
1993	54.997
1994	53.047
1995	52.504
1996	53.793
1997	55.211
1998	55.701
1999	56.487
2000	57.223
2001	56.807
2002	57.64
2003	56.287
2004	57.1
2005	57.204
2006	58.169
2007	58.116
2008	57.467
2009	56.269
2010	54.867
2011	54.124
2012	53.618
2013	53.177
2014	52.947
2015	53.027
2016	53.889
2017	54.123
2018	54.484
2019	54.933
2020	54.295
2021	55.121
2022	56.751
2023	56.55