Year	% of total
1990	0.4365287235900122
1991	0.41020031448690775
1992	0.6085707040824951
1993	0.5593945376768674
1994	0.743006993006993
1995	0.36811227424364434
1996	0.3844886301219378
1997	0.8353221957040573
1998	1.114892618237296
1999	1.1248185776487662
2000	1.8912251850111594
2001	2.110102558057291
2002	3.1898674797701423
2003	2.5100895757456443
2004	1.9215838509316772
2005	2.1166095051445373
2006	2.5071927661323468
2007	2.018047579983593
2008	2.6368018145732917
2009	4.5335459619546645
2010	3.1548904659055848
2011	3.358411541146358
2012	4.228294476476979
2013	2.2372881355932206
2014	4.153945042583962
2015	5.3278295094556976