Year	% of total
1992	16.297777777777778
1993	18.626031746031746
1994	34.39485401459854
1995	19.11854700854701
1996	14.268482490272374
1997	11.747574850299403
1998	11.730172910662825
1999	18.865594855305467
2000	22.146207865168538
2001	21.594555555555555
2002	26.209647435897438
2003	26.71671428571429
2004	24.479175531914894
2005	22.03488789237668
2006	20.499265033407575
2007	17.770846153846154
2008	18.173884007029876
2009	21.14013303769401
2010	23.235599078341014
2011	19.07730769230769
2012	15.706555944055944
2013	15.534745454545455
2014	15.658357664233577
2015	15.382172284644193
2016	16.345996055226824