Year	% of revenue
2009	8.593438053821064
2010	8.385418454433403
2011	8.383830683087414
2012	9.229824452384651
2013	7.045356056826492
2014	17.582646692874036
2015	15.465523199160655
2016	16.421324241949208
2017	18.505678330166845
2018	18.89499192527631
2019	19.804792711743694
2020	20.68431566778938
2021	24.772161949262923
2022	29.923822507292684