Year	% (national estimate)
1979	65.22
1980	64.68
1981	63.49
1982	62.65
1983	66.008
1984	63.997
1985	63.101
1986	62.733
1987	62.027
1988	61.496
1989	61.714
1990	61.204
1991	60.14
1992	59.412
1993	57.943
1994	56.711
1995	57.07
1996	56.92
1997	56.349
1998	56.475
1999	56.683
2000	57.561
2001	58.324
2002	58.047
2003	58.274
2004	57.859
2005	57.084
2006	56.86
2007	57.074
2008	57.405
2009	56.27
2010	56.074
2011	55.852
2012	55.482
2013	55.392
2014	54.567
2015	54.322
2016	54.427
2017	54.675
2018	54.806
2019	54.613
2020	54.071
2021	55.098
2022	55.681
2023	55.651