Year	% of revenue
1995	14.381094614776421
2001	23.407121610809195
2002	22.058068845602396
2003	19.661095636025998
2004	18.26943671021632
2005	19.486613303891804
2006	18.412630394900706
2007	15.760679781166337
2008	17.337094695782397
2009	22.907120642586662
2010	21.186552092066155
2011	21.53297787535448
2012	23.642316340701058
2013	20.815876433559115
2014	21.013597068479328
2015	33.72491455016136
2016	36.46789476853275
2017	36.46496095303803
2018	37.18496521722226
2019	37.305525747548934
2020	40.961245725110246
2021	40.695262581388
2022	37.723665346008275