Year	% of revenue
2000	9.147298297557365
2001	8.484299620876907
2002	8.34787062080886
2003	8.627212810986512
2004	8.021419944412916
2005	10.555235551182903
2006	10.85646718949794
2007	9.766059634242028
2008	8.754490451978503
2009	9.38924099478487
2010	10.523320702046158
2011	9.231782634101185
2012	8.891431071886023
2013	9.80549749159473
2014	7.945567814011764
2015	8.199989027668563
2016	6.909267345948569
2017	8.136890837409414