Year	% of total
1970	24.197921134866217
1971	22.72593622623412
1972	21.586552333783885
1973	20.690518520166933
1974	20.038341153224614
1975	19.087072876971384
1976	17.867521091352245
1977	17.177766567234855
1978	16.616273655138546
1979	16.053265715197647
1980	15.433808966830709
1981	15.248265819117535
1982	15.149409952831702
1983	14.862516263948876
1984	14.552242739178089
1985	14.13039468971548
1986	13.803136906887318
1987	13.251637827492194
1988	12.740644292895775
1989	12.21724998198286
1990	0
1991	0
1992	0
1993	0
1994	0
1995	0
1996	0
1997	0
1998	0
1999	0
2000	0
2001	0
2002	0
2003	0
2004	0
2005	0
2006	0
2007	50
2008	50