Year	% (national estimate)
1961	49.74
1972	39.63
1979	41.93
1980	41.92
1981	38.78
1982	42.04
1984	41.83
1986	48.41
1987	48.32
1989	48.6
1990	48.3
1991	42.64
1992	45
1993	45.23
1994	47.88
1995	51.59
1997	65.224
1998	63.579
1999	62.388
2000	62.568
2001	58.988
2002	79.677
2003	65.487
2004	67.529
2005	62.967
2006	66.024
2007	67.814
2008	68.485
2009	68.639
2010	69.114
2011	67.716
2012	67.245
2013	65.787
2014	64.133
2015	60.655
2016	60.541
2017	62.189
2018	62.053
2019	62.215
2020	55.936
2021	57.792
2022	59.25
2023	56.196