Year	% (national estimate)
1960	53.62
1961	53.517
1962	52.609
1963	51.299
1964	50.449
1965	49.973
1966	50.17
1967	50.437
1968	50.076
1969	49.563
1970	49.335
1971	48.247
1972	47.123
1973	47.634
1974	45.926
1975	44.959
1976	44.991
1977	45.809
1978	46.423
1979	46.671
1980	46.657
1981	46.655
1982	46.938
1983	47.682
1984	47.502
1985	47.378
1986	47.249
1987	47.247
1988	47.598
1989	48.32
1990	49.015
1991	49.551
1992	49.593
1993	48.977
1994	48.686
1995	48.352
1996	48.325
1997	48.686
1998	48.143
1999	47.38
2000	47.058
2001	46.819
2002	46.054
2003	45.888
2004	46.116
2005	46.327
2006	46.58
2007	46.626
2008	46.554
2009	46.179
2010	46.172
2011	46.15
2012	46.14
2013	47.001
2014	47.573
2015	47.933
2016	48.836
2017	49.722
2018	51.24
2019	52.119
2020	51.778
2021	52.18
2022	52.95
2023	53.564