Year	% of revenue
1999	10.941580934848155
2000	12.340199279022533
2001	11.07487971429624
2002	11.786590254174168
2003	15.866333760297756
2004	15.424724294251893
2005	15.391991195383707
2006	13.012998356714679
2007	13.487175984535254
2008	13.657808528284255
2009	10.045093711091214
2010	10.555922949991865
2011	12.81391869586418
2012	11.807719610422799
2013	11.619800029667516
2014	8.50997412912974
2015	11.149069897247347
2016	15.166477098878126
2017	14.503486162940185
2018	16.359446566997455
2019	16.991311379990222
2020	16.41962708714621
2021	17.267090338498083
2022	11.97265184407752