Year	% of total
1990	99.0385923624093
1995	99.1583231745692
2000	99.0322230013547
2005	99.0573645096537
2010	98.9439812737215
2011	99.2874133160782
2012	98.7488912607453
2013	98.2683688288714
2014	95.4166991515056
2015	91.6891503982034
2016	86.6060242865485
2017	86.604233540535