Year	% of total
1990	99.9795406500176
1995	99.9765662234224
2000	99.9832380736288
2005	99.9888189456023
2010	99.9852966777226
2011	99.987803292945
2012	99.9791742057402
2013	99.9726312338643
2014	99.962154535884
2015	99.9630307864801
2016	99.9418675096877
2017	99.9382823977342