Year	% of total
1990	1.45748987854251
1991	1.151108537955931
1992	1.6767306448134571
1993	2.820439213434764
1994	4.633521271143003
1995	2.7588757396449703
1996	2.0072655624653652
1997	2.057269947178204
1998	2.4310616218737247
1999	3.1706012682405076
2000	3.057279021670713
2001	2.269878846957248
2002	2.0469527003585055
2003	1.7261525387720418
2004	2.24509385665529
2005	3.1286853971557407
2006	3.2872402086610917
2007	3.1254639940608757
2008	3.0164328055826517
2009	2.8955815065218875
2010	10.812975570684822
2011	11.304757418747057
2012	9.33981011260764
2013	12.363550071191268
2014	10.760517799352751
2015	8.19633630812588