Year	% of total
1992	8.977424242424242
1993	8.970297743966421
1994	9.16891758156796
1995	9.229647140622284
1996	8.64704685362517
1997	7.073180355630821
1998	7.0994862834177885
1999	5.909352491815206
2000	6.629526325721834
2001	5.7194994201778115
2002	5.099942051381108
2003	4.947484300666032
2004	4.129237941545634
2005	4.025389518413598
2006	3.9095544975344327
2007	3.849231037489102
2008	3.3767794922847183
2009	3.6221241258741257
2010	3.698617211647958
2011	3.9717977720651243
2012	4.924905502592407
2013	5.249934924078091
2014	5.4755271565495205
2015	5.33782656221534
2016	5.718686832095635