Year	% of total
1990	90.7870462289057
1995	90.8524760100824
2000	92.2432250229349
2005	94.3283071510268
2010	94.5970786528437
2011	95.4309937077549
2012	92.0159982878997
2013	91.6863013697077
2014	89.7801066499698
2015	86.6606052498369
2016	81.118491956665
2017	81.2393235519484