Year	% (national estimate)
1978	64.55
1979	64.75
1980	65.76
1985	66.01
1986	66.85
1988	68.14
1989	68.84
1990	69.54
1991	77.704
1992	76.631
1993	75.831
1994	74.523
1995	74.966
1996	76.129
1997	75.186
1998	76.011
1999	76.025
2000	75.985
2001	76.081
2002	74.579
2003	73.861
2004	72.971
2005	72.179
2006	72.85
2007	73.558
2008	73.333
2009	72.404
2010	71.018
2011	71.641
2012	71.306
2013	70.776
2014	70.668
2015	70.732
2016	70.893
2017	71.071
2018	70.997
2019	70.618
2020	69.97
2021	69.111
2022	69.016
2023	69.974