Year	% of total
1990	2.0006487337918353
1991	2.3748087660751707
1992	2.6979271849484165
1993	2.917411211557298
1994	3.215423892718745
1995	3.986786696339215
1996	4.323010044429972
1997	6.712013062872524
1998	8.649092693169921
1999	8.451695201303492
2000	8.131258863985531
2001	6.927887181433929
2002	8.461510927360873
2003	8.066255818593035
2004	7.864693297135538
2005	6.2091457450993
2006	6.108381173928091
2007	6.120395423921959
2008	5.575090779466159
2009	7.74519028904639
2010	10.435596133728323
2011	9.410687172277118
2012	8.065219680360928
2013	8.012773477523266
2014	7.677108619333589
2015	7.802470461526829
2016	6.225096137567252