Year	% (national estimate)
1960	8.02
1973	6.26
1975	7.14
1976	8.49
1977	7.65
1978	9.32
1979	7.75
1980	8.25
1983	16.82
1984	18.21
1986	11.87
1989	26.55
1990	25.02
1991	20.85
1992	20.29
1993	20.23
1994	20.85
1995	19.89
1998	17.16
1999	20.32
2001	16.37
2002	19.57
2005	20.98
2006	19.48
2007	18.33
2008	18.394
2009	19.214
2010	18.615
2011	16.722
2012	16.528
2013	17.879
2014	18.077
2015	20.649
2016	20.3
2017	18.712
2018	11.38
2019	8.981
2020	7.407
2021	8.148
2022	7.813