Year	% (national estimate)
1960	76.17
1977	50.83
1979	49.45
1980	50.12
1981	49.1
1982	49.53
1983	48.976
1985	46.292
1986	48.07
1987	61.406
1988	57.791
1989	57.815
1990	59.953
1991	60.571
1992	60.691
1993	61.229
1994	61.558
1995	62.193
1996	61.286
1997	64.333
1998	67.258
1999	67.365
2000	73.386
2001	74.668
2002	75.06
2003	74.04
2004	72.23
2005	68.169
2006	68.084
2007	70.606
2008	71.43
2009	70.475
2010	67.921
2011	66.972
2012	67.722
2013	68.399
2014	67.018
2015	67.546
2016	67.223
2017	67.039
2018	67.989
2019	69.714
2020	67.658
2021	76.834
2022	81.683
2023	83.706