Year	% of total
1990	20.2169813871617
1995	14.6923107414309
2000	9.57763704069513
2005	7.96521936398286
2010	6.95746814695039
2011	10.9248519549833
2012	5.0797061093154
2013	4.40417299941835
2014	1.17923806606237
2015	2.53098843492732
2016	1.20245729264618
2017	1.214196134887