Year	% of total
1990	17.8654552323091
1995	17.9252992838954
2000	12.7891341987328
2005	12.4969311402171
2010	12.1619922157441
2011	12.0899817561924
2012	12.0164597672925
2013	0
2014	0
2015	11.7833379375932
2016	0
2017	0