Year	% of revenue
2001	35.63099127081883
2002	26.69515533377477
2003	41.07385715539177
2004	41.91528359928146
2005	51.64023392570753
2006	60.30467883695143
2007	57.29964910260931
2008	62.79384275398301
2009	47.47727758960959
2010	49.59734804349415
2011	64.2901809642921
2012	53.00396135191669
2013	48.64383315129951
2014	48.48389281938815
2015	36.64326132816757
2016	33.29182250157951
2017	22.48427672955975
2018	28.499089108413877
2019	26.091893689779543