Year	% of total
1990	99.9929864008889
1995	99.9927358753137
2000	99.996443700946
2005	100
2010	100
2011	100
2012	100
2013	99.9998083414663
2014	99.9961939277367
2015	99.9998034716169
2016	99.9422471818151
2017	99.9528372649131