Year	% of revenue
1995	2.367030457526753
1996	11.798911032404716
1997	20.615563298490127
1998	16.03111495246327
1999	17.317402076081162
2000	23.395728013845243
2001	19.281162262132895
2002	19.663417390690118
2003	18.247749701767706
2004	17.49522498586169
2005	20.39699881109219
2006	15.354971422619744
2007	16.40445355687628
2008	14.103367889373574
2009	15.378754480458493
2010	16.643142217463254
2011	13.423538479296132
2012	12.599324814943547
2013	12.36912641200605
2014	14.31351003114682
2015	10.318127967983115
2016	6.57582446764369
2017	5.606734466656024
2018	4.634447005895476
2019	6.419730326261183
2020	5.202023248399411
2021	7.342736929713214
2022	9.358283094166596