Year	% of total
1990	14.387986729526803
1991	15.738018732481029
1992	7.505705350350773
1993	8.7857847976308
1994	4.567307692307692
1995	4.589899919475441
1996	4.712732066351752
1997	5.565198524625732
1998	7.276141297969723
1999	7.486695694242865
2000	9.550099847292376
2001	9.642815041848403
2002	9.710331886947344
2003	7.864947337336352
2004	7.055512422360248
2005	7.760901518863303
2006	8.353884093711466
2007	5.118949958982773
2008	6.984216992722805
2009	6.276341268937237
2010	5.808392471459426
2011	5.630962537811215
2012	5.765856104286788
2013	3.902071563088512
2014	5.053832556644705
2015	7.151771143323414