Year	% of total
1970	76.92573560276772
1971	77.69981147683579
1972	77.28652162843484
1973	77.60250051011892
1974	76.52252038514604
1975	77.14814502643218
1976	75.06770945658671
1977	74.5715152063722
1978	73.55115638603453
1979	73.36729392124414
1980	71.94323314330936
1981	72.79634316380641
1982	71.51738146049766
1983	72.55603308788046
1984	73.39202954243962
1985	79.63819264725373
1986	79.82115110298767
1987	79.67215487290815
1988	77.26083318227232
1989	62.58556945185553
1990	100
1991	100
1992	100
1993	100
1994	50
1995	50
1996	50
1997	50
1998	50
1999	50
2000	50
2001	50
2002	100
2003	100
2004	100
2005	50
2006	50
2007	50
2008	50