Year	% of revenue
2004	3.155681821015386
2005	3.4386365451122525
2006	3.160685579059831
2007	3.437563449688188
2008	4.485931556701845
2009	3.475767477345687
2010	3.60305493286515
2011	3.934389976008713
2012	4.361769670577791
2013	4.255475084942302
2014	4.011283895674266
2015	5.133545005536146
2016	4.648717549500135
2017	5.70947836213009
2018	5.8768017663456416
2019	6.017673229664465
2020	4.410599919323575
2021	5.134469571316663
2022	2.8181115704639392