Year	% (national estimate)
1960	82
1970	67.01
1979	67.76
1981	58.34
1991	76.3
1992	79.2
1993	66.9
1994	67.7
1996	67.37
1997	71.32
1998	67.47
2000	59.669
2001	58.018
2002	55.903
2003	53.168
2004	53.765
2005	52.777
2006	53.814
2007	53.838
2008	54.104
2009	49.151
2010	49.071
2011	51.456
2012	51.15
2013	51.678
2014	52.13
2015	56.002
2016	56.867
2017	54.698
2018	56.256
2019	57.27
2020	50.561
2021	55.384
2022	56.093
2023	56.449