Year	% (national estimate)
1981	66.31
1982	65.6
1983	68.038
1984	67.092
1985	66.17
1986	65.531
1987	63.998
1988	64.011
1989	63.487
1990	62.803
1991	61.472
1992	60.875
1993	59.993
1994	60.471
1995	59.735
1996	60.248
1997	58.727
1998	60.026
1999	59.331
2000	59.442
2001	58.981
2002	59.12
2003	59.623
2004	59.339
2005	59.652
2006	60.251
2007	60.339
2008	60.513
2009	59.147
2010	56.825
2011	52.404
2012	47.691
2013	45.736
2014	45.662
2015	46.531
2016	47.624
2017	48.994
2018	50.541
2019	51.539
2020	50.555
2021	51.939
2022	54.763
2023	54.92