Year	% of revenue
2003	10.184579938755327
2004	9.373805020250819
2006	7.178714362306077
2007	5.669237810195143
2008	4.844933106743769
2009	6.031554058327191
2010	5.163142844668185
2011	5.174305840460474
2012	5.031689248462142
2013	5.3587196380424515
2014	5.286035899275715
2015	6.281478324187672
2016	7.508617023083566
2017	7.528570116439309
2018	9.007485428885067
2019	7.98549286756141
2020	8.795608395041837
2021	7.9846690333231125