Year	% of total
1970	97.79918648416006
1971	97.94918180220598
1972	98.11323663208113
1973	97.94834601918886
1974	97.77754633398649
1975	97.5586446140693
1976	95.35608380615065
1977	96.64002413282972
1978	96.5419212744465
1979	96.4892258970257
1980	96.43346986730185
1981	97.17773379031419
1982	97.09692183762145
1983	97.01555424176118
1984	96.93709907124511
1985	96.97202752159272
1986	97.05987463073707
1987	97.12095439207114
1988	97.1580548203771
1989	97.19100638359129
1991	0
1992	0
1993	0
1994	0
1995	50
1996	50
1997	50
1998	50
1999	50
2000	50
2001	50
2002	50
2003	50
2004	50
2005	50
2006	50
2007	50
2008	50