Year	% of revenue
2005	2.3339497395393147
2006	2.9250893055894167
2007	1.5130674002751032
2008	1.0726932302937122
2009	1.8494941895123833
2010	1.386268422643575
2011	1.89979635618381
2012	2.3365445783704195
2013	2.451528764501431
2014	1.7354389931009417
2015	2.4830237986283357
2016	1.845690559534164
2017	1.7315769135226762
2018	1.619493753652339
2019	1.6351058788263124
2020	3.0261495485366123
2021	2.736028084713378