Year	% of total
1990	14.613624361908114
1991	19.415591049960835
1992	12.51347854216088
1993	7.169513420410506
1994	12.752434648898001
1995	7.684911242603551
1996	7.905917123329845
1997	10.272449263274952
1998	16.04384072756952
1999	13.094965237986095
2000	5.575038215987771
2001	4.532794875365548
2002	2.711923210361975
2003	1.5721266199277673
2004	1.2372013651877134
2005	1.2833853624696496
2006	1.6808810134967294
2007	2.1009651076466223
2008	4.217003076461319
2009	5.0194632247490265
2010	12.955546655987185
2011	4.922279792746114
2012	5.299183042614263
2013	4.888467014712862
2014	4.314994606256742
2015	6.458431188351339