Year	% of revenue
1994	6.592547389297837
1995	13.091240317091335
1996	11.476432951535456
1997	14.589514272271115
1998	12.856350070910324
1999	11.302827428620239
2000	10.841576651994991
2001	9.349383180927132
2002	11.382334491958462
2003	11.06822826855815
2004	15.034885974001904
2005	14.78430262665029
2006	16.54359469448745
2007	13.438903746914669
2008	14.28045164418987
2009	20.392177024980562
2010	23.820347648528745
2011	22.955640382399935
2012	21.44416072563104
2013	19.81517633777589
2014	19.434218328102062
2015	18.520493536080394
2016	16.521004743964475
2017	16.143791108068058
2018	18.128155904743373
2019	17.87982856772585
2020	18.003372914171287
2021	17.177719401369966
2022	13.790414444105886