Year	% of revenue
2005	31.278947411378304
2006	33.776062922015285
2007	30.628152223750575
2008	21.010473490433554
2009	43.878562697199
2010	35.472718906140734
2011	39.78732875659056
2012	42.43872432006374
2013	36.41467958917749
2014	39.99498923664328
2015	45.2876761461379
2016	46.007826751367574
2017	43.835411281165634
2018	40.63885869529524
2019	44.2090843449396
2020	42.13566551318652
2021	41.171210192266166