Year	% of total
1990	94.9167422311179
1995	96.714973586697
2000	97.675931904665
2005	97.7772447875165
2010	97.5231033997369
2011	99.1758003072292
2012	95.7057987437172
2013	89.2152097885957
2014	28.9425335999641
2015	28.4404306073516
2016	2.68187796570906
2017	2.68715857042922