Year	Percent
1961	24.86777
1962	24.86777
1963	24.86777
1964	24.86777
1965	24.86777
1966	24.86777
1967	24.86777
1968	25.40223
1969	25.40144
1970	24.63093
1971	24.65461
1972	24.61277
1973	24.3262
1974	23.50991
1975	23.50991
1976	23.50991
1977	23.50991
1978	23.50991
1979	23.65043
1980	24.25199
1981	23.90463
1982	23.96779
1983	24.48093
1984	24.29936
1985	24.29936
1986	24.69409
1987	24.48251
1988	24.70988
1989	24.79277
1990	26.08905
1991	26.92429
1992	27.63085
1993	27.63085
1994	27.63085
1995	28.4203
1996	28.4203
1997	28.4203
1998	28.4203
1999	29.20976
2000	29.20976
2001	29.99921
2002	29.99921
2003	30.32447
2004	30.37183
2005	33.91884
2006	33.93779
2007	34.56383
2008	34.56383
2009	34.56383
2010	34.72172
2011	35.11644
2012	35.35328
2013	36.06379
2014	36.06379
2015	36.07405
2016	36.62667
2017	36.78456
2018	36.78456
2019	36.78456
2020	36.78456
2021	36.78456