Year	% of total
1990	99.9816845986973
1995	99.9815721201174
2000	99.9673515864133
2005	99.9677573474524
2010	99.9684096538509
2011	99.9685195195117
2012	99.9434717498816
2013	99.9272010224121
2014	99.9178608517105
2015	99.8282838822608
2016	99.674855479732
2017	99.6772126159304