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	3.1460296096904443
2003	8.124025636584097
2004	9.616280876184558
2005	11.345167652859962
2006	12.206039076376554
2007	12.27095040312729
2008	9.342615719827815
2009	10.657547525445635
2010	11.230714029422318
2011	9.423676012461058
2012	10.228914080623277
2013	12.87562873479214
2014	13.341835685193566
2015	12.667440960123887