Year	% of total
1990	4.71769108889696
1995	3.99615187176842
2000	2.59981543690511
2005	1.48059997808411
2010	2.24690296214172
2011	8.17116625332683
2012	1.11084437425552
2013	0.891205669083017
2014	0.931903874855
2015	1.17173902285453
2016	0.647888972585253
2017	0.812676876908647