Year	% of revenue
2000	3.3075998056602947
2001	4.305091093637414
2002	3.4905098545435047
2003	4.01537170436117
2004	4.04576491730495
2005	4.444641315646972
2006	2.880961946066059
2007	8.245568969946056
2008	10.30419504207801
2009	10.048596367586443
2010	10.78550058396574
2011	11.8818112655739
2012	16.74486518709038
2013	10.973697607330731
2014	7.571497818710615
2015	6.463844757813693
2016	2.989676900388792
2017	2.359124087591241
2018	2.444109273757124
2019	2.0680067113488763
2020	1.6910997180716143