Year	% of revenue
1994	19.27072464183937
1995	20.639626334722287
1996	19.38086077754074
1997	19.792304596527494
1998	20.416628072986725
1999	19.834915138961883
2000	20.627316443690493
2001	19.511395006664394
2002	20.118459490606323
2003	19.3740574278419
2004	18.680174460828333
2005	18.206571956571956
2006	19.230466686570388
2007	18.971123616301856
2008	19.17945871806618
2009	17.447887928063636
2010	17.40050576609215
2011	15.497475738667893
2012	16.086861039566482
2013	16.355786258455726
2014	17.0733677407225
2015	17.025910471382794
2016	17.55846325735641
2017	18.09848925985419
2018	17.96269651380335
2019	17.83907708134323
2020	17.278068857753848
2021	17.567004778082726
2022	18.64605474776286