Year	% of revenue
1999	9.790828457217573
2000	9.154712406554728
2001	6.884744983783575
2002	3.97151754665216
2003	3.054940738772035
2004	2.827774047871049
2005	2.0846486739770347
2006	1.6992355150889416
2007	1.48349405379304
2008	1.2717188962482666
2009	3.0555530710818886
2010	4.394515775306727
2011	5.174305840460474
2012	4.875080877968444
2013	6.4609950158571
2014	8.25599069962685
2015	12.122399955425115
2016	12.937074875799995
2017	11.390656032945001
2018	10.086513150949814
2019	9.38918966102365
2020	8.769683457423511
2021	9.265518484774649
2022	7.2032622167390326