Year	% of revenue
2005	35.566573701063945
2006	35.300945561041814
2007	38.176513903551054
2008	39.27126125221081
2009	36.39658484920747
2010	40.18028569977187
2011	39.058827339290175
2012	37.13607476990048
2013	37.81799504986421
2014	41.557780784136696
2015	39.12559091624761
2016	35.5795348455608
2017	38.59228641136693
2018	37.55239516972726
2019	29.632411104157864
2020	36.6615339143472
2021	37.5471095982227
2022	36.12760547837325