Year	% of total
1992	27.911986339730298
1993	23.837359766487523
1994	22.547599117263548
1995	21.125862692050056
1996	19.826188701758152
1997	18.679478659624987
1998	16.420413630628037
1999	14.574703869805816
2000	16.112877575296377
2001	15.7023425386717
2002	14.731253755827815
2003	15.193903011411328
2004	14.813271714054247
2005	14.892710232428517
2006	13.314065004754394
2007	13.844750960188673
2008	13.411495410371735
2009	11.592421753456975
2010	13.624339303815649
2011	12.821326678903493
2012	12.023095065884064
2013	13.570127995002398
2014	13.149522944643223
2015	12.023878964257284
2016	11.901485812269259