Year	% of total
1970	4.16509394339271
1971	3.949211384335147
1972	3.830646899563418
1973	3.733940540096177
1974	3.8189377031955165
1975	3.636022743688466
1976	2.920593533463271
1977	2.707382430061773
1978	2.9096873108352472
1979	3.933520102257419
1980	3.9095294188238863
1981	2.604196260282336
1982	2.0835124549914186
1983	3.3993637237698464
1984	3.1967449000858843
1985	3.428047045912682
1986	3.1287154292104957
1987	3.0734776846683087
1988	6.075963344392058
1989	5.605369855142028
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	0
2008	0