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	2.2224364318579735
1985	2.862165922779282
1986	4.583538351123779
1987	3.130933282401173
1988	5.090781163271445
1989	5.211500722202677
1990	3.8667907664067664
1991	4.140829682831697
1992	4.250650477745139
1993	3.2014037139890497
1994	4.149434052241594
1995	4.679019666904343
1996	4.603900229835115
1997	4.768023045499194
1998	5.108086240733038
1999	4.816205135614596
2000	4.681261001162296
2001	3.780810090750944
2002	4.026181869997804
2003	4.069472303974123
2004	4.0921295281724515
2005	3.3961720489590896
2006	2.9037571376574642
2007	3.153267904021707
2008	3.672837683064815
2009	3.665910150952123
2010	3.306397931178747
2011	3.608978907152659
2012	3.2128620158108925
2013	3.732574051516578
2014	3.5800377804176167