Year	% of total
1990	7.21714275299105
1995	7.04366699422421
2000	7.85463095573879
2005	8.56213148419362
2010	3.19405070238882
2011	2.2790250221414
2012	0.431712693785835
2013	2.10368093519507
2014	5.98473368240575
2015	17.3946725496383
2016	20.0946023238116
2017	21.8661236988959