Year	% of total
1971	0
1972	0
1973	0
1974	0
1975	0
1976	0
1977	0
1978	0
1979	0
1980	0
1981	0
1982	0
1983	0
1984	0
1985	0
1986	0
1987	0
1988	0
1989	0
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	0.002413942934389031
2005	0.011370872373328482
2006	0.043954111907168913
2007	0.10946270116682581
2008	0.30952808182307556
2009	0.5851678818338406
2010	1.5885433644088054
2011	2.035063870619515
2012	4.510616372184891
2013	6.605679258863684
2014	5.930487778890617
2015	6.37437938533503