Year	% of total
1960	0
1961	0
1962	0
1963	0
1964	0
1965	0
1966	0
1967	0
1968	0
1969	0
1970	0
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	1.0087839692561076
1986	1.809440275476724
1987	1.2411407643528094
1988	2.2800142500890628
1989	3.0174857192691755
1990	2.671079978446617
1991	2.2684361745792856
1992	3.5168195718654434
1993	4.67710602225231
1994	5.618808221203608
1995	9.889003754284783
1996	10.59870852151842
1997	15.299559968407989
1998	19.76990246394085
1999	23.268242548818087
2000	24.336393642692702
2001	24.577910890826686
2002	24.410110214574797
2003	21.14060537825315
2004	24.584528637847463
2005	24.223362577939636
2006	20.611256056653
2007	17.898565469528947
2008	19.341271575267644
2009	18.335486353516753
2010	20.34378055684216
2011	16.58009026654177
2012	13.654278362268329
2013	9.835074691304724
2014	6.490802883420333
2015	6.273534390437696