Year	% of revenue
2000	25.563333013711762
2001	28.484905394619464
2002	43.744197274111485
2003	46.240717070881935
2004	45.07806808279645
2005	39.86730143886173
2006	32.36155043917523
2007	34.81825126582663
2008	38.65385261125722
2009	43.641299426640664
2010	45.94662690250926
2011	38.435750370342234
2012	38.54495175779922
2013	37.81092626414691
2014	34.07227488905128
2015	36.548033897163265
2016	35.47809603075257
2017	32.795383772223666
2018	34.91621731402641
2019	30.738774786319418
2020	23.65012337564672
2021	34.89740689863077