Year	Percent
1961	14.2779
1962	14.2779
1963	14.2779
1964	14.3326
1965	14.3326
1966	14.3326
1967	14.3326
1968	14.38731
1969	14.38731
1970	14.38731
1971	14.38731
1972	14.44201
1973	14.44201
1974	14.44201
1975	14.44201
1976	14.49672
1977	14.49672
1978	14.49672
1979	14.49672
1980	14.49672
1981	14.49672
1982	14.87965
1983	15.31729
1984	15.86433
1985	15.20788
1986	14.60613
1987	14.00438
1988	13.45733
1989	12.91028
1990	12.69147
1991	12.52735
1992	12.58206
1993	12.58206
1994	12.63676
1995	12.74617
1996	12.85558
1997	13.01969
1998	13.1291
1999	13.29322
2000	13.40263
2001	13.56674
2002	13.67615
2003	13.32604
2004	12.94311
2005	12.58753
2006	12.28665
2007	11.93107
2008	11.52079
2009	11.24726
2010	10.86433
2011	10.41028
2012	10.06751
2013	10.05088
2014	10.05088
2015	10.06729
2016	10.06729
2017	10.06729
2018	10.06729
2019	10.06729
2020	10.06729
2021	10.06729