Year	% of revenue
2008	5.914507494276882
2009	3.9339590053571682
2010	4.131749027957081
2011	5.721673429949695
2012	5.438242599397479
2013	8.237379111075747
2014	27.792431391733867
2015	7.54875076587035
2016	8.013463266445106
2017	15.901961015097454
2018	43.19855256257268
2019	35.5568168973782
2020	10.935049062492512