Year	% of total
1990	3.84299357672015
1995	4.04697849883131
2000	5.3611363337938
2005	4.65963858101909
2010	5.63328281652253
2011	5.10035575615576
2012	5.11729003546617
2013	5.78173283349338
2014	5.22094719256993
2015	5.92309695517031
2016	5.3594880946364
2017	6.06519386355592