Year	% of total
1990	23.455377574370708
1991	23.57842513675105
1992	25.46957719921677
1993	12.180214790884484
1994	5.195996026591273
1995	17.423871193559677
1996	16.82878758980228
1997	17.164858242912146
1998	13.127258129265353
1999	10.27237354085603
2000	9.811800951041457
2001	9.563181385819858
2002	9.327294078174802
2003	10.462877112902074
2004	10.65979789974242
2005	3.0353905043314757
2006	2.926392618604971
2007	2.5960890087660147
2008	1.883111375010603
2009	0.7218262203374537
2010	1.4958677685950412
2011	1.0093679905000659
2012	0.5340189873417721
2013	0.19270573121119122
2014	0.8029096898160856
2015	1.3046815042210285