Year	% of revenue
2006	5.758616983906333
2007	4.312935693670451
2008	1.7805904290944492
2009	2.9995269643096325
2010	3.03014411721057
2011	2.6224248549744984
2012	3.119213992886703
2013	2.535723129614733
2014	2.550026172373742
2015	2.6542410762172017
2016	7.055293341474165
2017	8.598224048284228