Year	% of total
1990	99.7982044933026
1995	99.8021571840564
2000	99.9049802360953
2005	99.9077432962499
2010	99.9103802712244
2011	99.9108887765813
2012	99.8390958225777
2013	99.7316196812428
2014	96.4580758151654
2015	99.3894442142846
2016	90.7268954280059
2017	90.8564088569626