Year	% (national estimate)
1960	23.01
1970	26.32
1973	43.55
1976	39.16
1980	34.82
1985	45.74
1986	45.8
1987	47.24
1988	46.95
1989	48.199
1990	48.522
1991	46.82
1992	53.966
1993	52.08
1995	50.946
1996	49.772
1997	50.304
1998	50.744
1999	51.872
2001	52.428
2002	54.52
2003	54.195
2004	55.609
2005	57.3
2006	56.027
2007	56.106
2008	55.437
2009	55.251
2011	51.593
2012	48.559
2013	47.529
2014	47.015
2015	47.054
2016	48.091
2017	49.396
2018	49.437
2019	50.749
2020	44.513
2021	48.626
2022	50.084
2023	48.289