Year	% of revenue
1992	10.969378716161492
1993	9.686783955056178
1996	11.67414436400602
1997	8.096769552756587
1998	4.5166531989535725
1999	4.425876101700913
2001	4.175398483654564
2002	4.800155871807595
2003	4.070555819749113
2004	3.7785981613863955
2005	2.8009126471935204
2006	4.403642337596509
2007	3.2713920272219665
2008	4.835614499333857
2009	3.735231616090483
2010	4.2259397487891
2011	4.450315389209793
2012	3.711288659023304
2013	3.2986376589977064
2014	3.118478070598229
2015	3.153167701611149
2016	3.387266117275095
2017	3.147533340152364
2018	3.1031635900598245
2019	2.901695474008825
2020	2.994193980240572
2021	3.3207147516472566
2022	2.724749634984853