Year	% of revenue
2005	33.161653482293566
2006	33.1080139316109
2007	33.245160250713454
2008	36.793036688497224
2009	38.87620615543996
2010	39.00236848592478
2011	39.38014950768212
2012	38.92150219688456
2013	39.739390071733965
2014	39.01544543840539
2015	39.079205627189175
2016	39.14412423259143
2017	38.872048475671924
2018	38.6248991193293
2019	39.43220307783094
2020	41.11740209012712
2021	40.074805048834214
2022	39.40228521650047