Year	% of revenue
1992	1.1840157868771573
1993	2.9881154499151115
1994	3.5743298131600367
2002	5.320882511438202
2003	4.760083338035923
2004	4.116498709892897
2005	3.7463443070825955
2006	3.415937712178347
2007	3.1369721368449968
2008	2.73544801860734
2009	3.3457412445120265
2010	4.093854700144208
2011	4.753708111041769
2012	4.977422817636829
2013	6.274582839220743
2014	8.027417644701377
2015	7.811580644141723
2016	7.666339729670291
2017	6.404986644069684
2018	5.108081448024769
2019	4.312692896639974
2020	4.083259972805913
2021	3.0868886497453816
2022	2.8268295359482187