Year	% of total
1990	92.93216032223039
1995	92.4312393935602
2000	92.05023184441305
2005	91.91243472960174
2010	91.39501215688249
2011	92.3774687396628
2012	89.56084718609895
2013	88.19833815121001
2014	84.45986966721871
2015	85.60825490787217
2016	79.81303140716521
2017	79.86462312948211