Year	% (national estimate)
1975	63.53
1990	73.048
1991	71.46
1992	68.206
1993	64.17
1994	63.327
1995	62.941
1996	55.457
1997	54.493
1998	54.804
1999	56.249
2000	57.105
2001	59.771
2002	59.553
2003	59.268
2004	58.35
2005	58.159
2006	58.876
2007	59.763
2008	59.949
2009	58.023
2010	64.461
2011	65.4
2012	65.46
2013	65.745
2014	66.232
2015	66.651
2016	67.053
2017	67.838
2018	68.33
2019	68.344
2020	67.212
2021	60.699
2022	61.967
2023	62.389