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	0.7377979568671964
1983	1.7258464079273328
1984	1.5930113052415211
1985	1.5888778550148956
1986	1.1893166555595427
1987	3.129488574537541
1988	4.015713662156264
1989	3.633280415644393
1990	3.443842409771329
1991	2.8093197643277987
1992	2.611230217040445
1993	2.409691629955947
1994	3.7754585458935312
1995	3.7419965198587675
1996	3.4803024038745494
1997	3.4973937046913317
1998	3.3599015864066226
1999	3.181051038817436
2000	5.223680685775515
2001	5.964208821379896
2002	5.774508626186274
2003	5.5844707631844495
2004	5.555786723034545
2005	5.195680982364795
2006	5.02735361308164
2007	4.964439223079683
2008	5.595810508551759
2009	5.971653462946662
2010	5.570969927248093
2011	5.221980514347089
2012	4.838274258861171
2013	4.4361633182112765
2014	4.821481858554653
2015	4.778531865426696