Year	% of total
1990	4.6318859571703195
1991	4.201535588224209
1992	3.4431261687399886
1993	3.067271865091659
1994	3.265595169697706
1995	2.385189242671775
1996	2.263677237835329
1997	1.9817744821628671
1998	2.778533609597731
1999	2.4462280804107848
2000	2.427065420077724
2001	2.221107559598086
2002	2.1417756133222654
2003	1.8461045841709547
2004	1.6514746033667187
2005	1.7392799414123163
2006	1.78770883285812
2007	1.8763531966252323
2008	1.5235519789808576
2009	1.2662064770957768
2010	1.7180354695581317
2011	2.145506830413452
2012	1.6151788460388468
2013	1.991939936860835
2014	2.2402441697634328
2015	2.2776614438414517
2016	2.180014912977469