Year	% of total
1990	45.38658419760143
1991	44.49776424787162
1992	45.09684706925175
1993	45.62652375328517
1994	45.53141426063791
1995	44.773076601673885
1996	44.63148167943293
1997	43.94744790198328
1998	43.931729302691586
1999	44.141001529089735
2000	44.05051407465533
2001	43.97213763872745
2002	43.915564803117846
2003	43.89608298490883
2004	43.95959648224142
2005	43.82387978348422
2006	43.70257639205477
2007	42.35349365841461
2008	42.30535182255821
2009	43.540648644594704
2010	41.97855821037816
2011	41.35511956519768
2012	41.93162453768501
2013	41.16450698308769
2014	41.81935232462485
2015	41.900840986014224
2016	41.30140055141819