Year	% of total
1990	93.8196237795152
1995	94.3992175713122
2000	94.0805974788876
2005	96.900644536307
2010	97.0371658027196
2011	96.5159135409456
2012	96.1869911806579
2013	95.6872719982894
2014	89.1942294609304
2015	70.5389265622539
2016	55.5204961002275
2017	55.7946705406718