Year	Percent
1961	18.90838
1962	18.90838
1963	19.10331
1964	19.10331
1965	19.10331
1966	19.10331
1967	19.10331
1968	19.10331
1969	19.10331
1970	19.10331
1971	19.68811
1972	19.68811
1973	21.4425
1974	21.63743
1975	20.66277
1976	20.66277
1977	20.66277
1978	20.66277
1979	20.66277
1980	19.68811
1981	18.51852
1982	17.154
1983	14.42495
1984	14.42495
1985	13.84016
1986	13.84016
1987	13.84016
1988	14.03509
1989	14.03509
1990	15.00975
1991	15.78947
1992	15.78947
1993	15.78947
1994	15.78947
1995	14.81481
1996	14.81481
1997	13.84016
1998	12.8655
1999	13.06043
2000	13.06043
2001	11.69591
2002	11.69591
2003	11.69591
2004	10.72125
2005	10.52632
2006	10.52632
2007	10.52632
2008	10.52632
2009	10.52632
2010	10.52632
2011	10.52632
2012	10.52632
2013	10.52632
2014	10.52632
2015	10.52632
2016	10.52632
2017	10.52632
2018	10.52632
2019	10.52632
2020	10.52632
2021	10.52632