Year	% of total
1990	5.215350471507264
1991	4.663681108253735
1992	20.068319863029483
1993	17.56534315368419
1994	16.979313491956
1995	15.848297582334737
1996	15.010522865973362
1997	14.269141743938269
1998	12.511739960841455
1999	11.197335138280382
2000	12.382699579017457
2001	11.928844737087038
2002	11.332027545755194
2003	11.592454955932864
2004	11.238831888308354
2005	11.389475377838261
2006	10.090896579607728
2007	10.641292131869616
2008	10.591638846927024
2009	8.709913031929197
2010	10.882254228341141
2011	10.28115311199056
2012	9.646315911915782
2013	11.039165679515593
2014	10.801767448993886
2015	9.903340676399981
2016	9.87590849885531