Year	% of revenue
1999	6.612761057859625
2000	18.584204425823327
2001	22.354459999193125
2002	21.078512237718538
2003	19.48595274128205
2004	19.70146158229587
2005	16.339355651724823
2006	15.980974922037031
2007	15.704435312860868
2008	17.42311785394702
2009	18.311235739163987
2010	19.554149244775545
2011	15.803860832736005
2012	16.89495518347799
2013	15.66710467225843
2014	25.582321135062386
2015	16.66438811543052
2016	19.671383651767805
2017	19.98100945971269
2018	17.573459943159975
2019	18.392630741282513
2020	19.443407816504067
2021	15.533639255333995
2022	41.17463109565171