Year	% of total
1960	97.81420765027322
1961	93.52094240837697
1962	91.23287671232877
1963	87.4538745387454
1964	81.96500672947509
1965	82.13566151779717
1966	79.98570407433881
1967	75.39118065433856
1968	76.17709065354885
1969	77.08333333333334
1970	74.72365512159175
1971	63.16579144786196
1972	55.99415204678363
1973	58.82352941176471
1974	57.48792270531401
1975	46.67931688804554
1976	33.941605839416056
1977	33.098591549295776
1978	37.050043898156275
1979	38.97996357012751
1980	51.633986928104584
1981	57.692307692307686
1982	56.82656826568265
1983	58.723404255319146
1984	67.28624535315984
1985	72.25433526011561
1986	65.47619047619048
1987	60.207612456747405
1988	62.33766233766234
1989	70.25316455696202
1990	76.4423076923077
1991	74.89300998573466
1992	71.51515151515152
1993	74.96274217585693
1994	66.72443674176776
1995	38.809034907597535
1996	30.227272727272727
1997	20.689655172413794
1998	0
1999	0
2000	0
2001	0
2002	0
2003	0
2004	0
2005	0
2006	0
2007	0
2008	0
2009	0
2010	0
2011	0
2012	0
2013	0
2014	0
2015	0