Year	% of total
1990	99.9698219957482
1995	99.9701829894742
2000	99.9855662754186
2005	99.9859520400723
2010	99.9865938333289
2011	99.9867397491276
2012	99.9868891393068
2013	99.9870422790225
2014	99.9819899579683
2015	99.9799228143435
2016	99.6575386303828
2017	99.6656660324458