Year	% (national estimate)
1961	80.31
1971	70.59
1980	59.11
1981	68.55
1982	60.78
1983	61.57
1984	64.42
1985	63.42
1986	64.09
1987	65.68
1988	64.44
1989	63.58
1990	63.21
1991	63.61
1992	64.36
1993	61.71
1994	62.252
1995	61.743
1996	59.619
1997	58.412
1998	58.549
1999	58.367
2000	56.075
2001	54.684
2002	55.743
2003	54.706
2004	55.74
2005	56.965
2006	56.83
2007	58.376
2008	58.605
2009	58.475
2010	57.216
2011	58.005
2012	58.152
2013	57.742
2014	57.075
2015	56.495
2016	56.66
2017	54.936
2018	55.813
2019	55.479
2020	55.557
2021	55.699
2022	56.612
2023	58.161