Year	% of revenue
2002	12.555806921518176
2003	11.898899264247873
2004	10.890187022775109
2005	8.873465582754674
2006	7.667361393373865
2007	6.241284488075957
2008	6.842777798107995
2009	6.06732840338994
2010	5.828189707518565
2011	5.3120603355528875
2012	5.318375458228825
2013	6.178919210506336
2014	6.567755677246412
2015	7.5295179648221575
2016	8.5196308096913
2017	8.334980235671445
2018	10.13426498388108
2019	8.941324708440261
2020	10.168949750999351
2021	8.812124952995735