Year	% of total
1990	99.67363975003893
1995	99.66829393806611
2000	99.59836237437385
2005	99.84744517567997
2010	99.51040131821192
2011	99.7193036766008
2012	99.90920471624652
2013	99.16688650599203
2014	99.13322911768388
2015	99.38248585843665
2016	99.13739047037258
2017	99.09173596311486