Year	% of total
1971	0.11277613071985766
1972	0.09822759658758823
1973	0.19046623419692976
1974	0.3122834072819288
1975	0.5234350801604054
1976	0.6806143679371565
1977	0.5721312531168861
1978	0.617521001599249
1979	0.581367313041909
1980	0.5299715032077252
1981	0.6580218338879392
1982	0.6076756550434255
1983	0.7509118520966668
1984	0.9714694599446105
1985	1.102531369793207
1986	1.0019951860143872
1987	0.9158327132535036
1988	1.0746472637450024
1989	0.9859624121246974
1990	5.991447670349
1991	5.856728576295136
1992	5.7461465359941695
1993	5.6685308878587914
1994	5.297086306515817
1995	5.379924425990019
1996	5.731008491433659
1997	5.7086847932322335
1998	5.419457186097172
1999	5.512902784950722
2000	5.615983791540834
2001	5.718247000986351
2002	5.702732918448886
2003	5.712117100896382
2004	5.373479582277221
2005	5.141155833640832
2006	4.943821746008535
2007	4.673206255277903
2008	4.626192551497349
2009	4.47740976589142
2010	4.302376060694949
2011	4.268935137669535
2012	4.210766857502231
2013	4.066285823968507
2014	4.204937032746079
2015	0.09165421694715545