Year	% of revenue
2004	10.533697594043735
2005	7.090348609517341
2006	5.266559412179826
2007	5.562608903987745
2008	4.32528839610002
2009	4.0230609164628355
2010	4.191144125529059
2011	2.8836328290506694
2012	4.663320238442852
2013	5.3587196380424515
2014	5.982856782800637
2015	8.073598574186645
2016	10.39483766836075
2017	7.964325512321406
2018	9.89769001763765
2019	11.49538619231162
2020	14.138094328555828
2021	12.954159601105102
2022	13.952397341697468