Year	% of revenue
2002	29.689988248063067
2003	32.48400923904104
2004	37.70972333842751
2005	36.903302093856595
2006	40.27556402146368
2007	40.416272040162156
2008	41.67023820306745
2009	35.4708878629919
2010	35.29049153480938
2011	39.2845687277783
2012	35.35727108932336
2013	38.04889406541038
2014	42.03783238324116
2015	45.88749917341615
2016	44.036062454311434
2017	45.77111875902468
2018	48.049242413028985
2019	50.42128391283091
2020	47.3441308041456
2021	46.009500247566024