Year	% of revenue
2008	81.7456447284423
2009	86.19105712478388
2010	86.72149372441146
2011	84.94376251494457
2012	86.54110484690264
2013	82.70351114098548
2014	64.88744404290351
2015	84.4677507669935
2016	84.43473741105049
2017	77.67552365896223
2018	50.86968004192476
2019	58.11657021261231
2020	80.97226131195619