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
2005	0
2006	0.0025895331071807753
2007	0.0025672622715136578
2008	0.002631994525451387
2009	0.002581844469689146
2010	0.24226951832651678
2011	0.20456172650097168
2012	0.23427041499330656
2013	0.2426068747127024
2014	0.2656042496679947
2015	0.2787273205364186