Year	% of revenue
1995	10.947830953219889
1996	11.491864774727613
1997	10.690361426419072
1998	12.682308123973563
1999	13.039471511147813
2000	11.933618504435994
2002	11.577699547381277
2003	11.31478496104848
2004	10.985130485522848
2005	6.059916754312237
2006	4.613516433475897
2007	3.5966983655706914
2008	4.715421404231232
2009	4.490155916726909
2010	4.394515775306727
2011	5.3120603355528875
2012	4.948068349212147
2013	5.596032571594286
2014	6.3545584960433485
2015	6.9053268935608765
2016	8.5196308096913
2017	7.634136573068925
2018	8.85043083374509
2019	8.182512685895484
2020	10.168949750999351
2021	8.364315571132025
2022	9.472593793301549