Year	% of total
1990	99.989331054587
1995	99.9897129196054
2000	99.9792857085907
2005	99.9793091765736
2010	99.9800386871922
2011	99.9802363564386
2012	99.9804425907676
2013	99.9806572067221
2014	99.9808802620286
2015	99.9811120648255
2016	99.9813525837306
2017	99.9815995770005