Year	% of total
1990	6.801152675682229
1991	4.613272419821
1992	4.037848231071047
1993	3.875726313333903
1994	3.2864282599663013
1995	4.145490439326929
1996	3.3531836707138547
1997	3.8384822496341493
1998	2.2816225423283174
1999	2.8066472301062686
2000	4.534170656652146
2001	4.645300166520176
2002	4.043809257834253
2003	3.357751704070453
2004	3.338671294690076
2005	3.4193185363230336
2006	3.3362654367237257
2007	3.9321125908024586
2008	4.070583301551641
2009	4.430008430121178
2010	5.211956733245431
2011	6.248931350553469
2012	6.1069156926652175
2013	6.144130239926958
2014	6.952232661310525
2015	10.393136209406876
2016	12.7060517822547