Year	% of total
1992	12.191460234680575
1993	10.091356589147289
1994	3.7517161716171623
1995	2.045338645418327
1996	0.9822321428571429
1997	2.4836254980079677
1998	1.727210144927536
1999	1.2993307086614174
2000	2.000181818181818
2001	3.0700465116279068
2002	3.7875117370892024
2003	4.900599078341014
2004	6.253798449612404
2005	6.884979591836735
2006	6.592359550561798
2007	9.703446153846155
2008	11.255148514851486
2009	12.888200836820085
2010	13.940661157024792
2011	14.581377952755906
2012	23.547290969899663
2013	27.734588607594933
2014	33.14246085011186
2015	36.978151260504205
2016	37.46984899328859