Year % of revenue 1993 7.019235016408095 1994 7.345863530827295 1995 8.928678791522621 1996 7.2896876957401755 1997 6.551428488855636 1998 7.170064236281074 1999 6.757219236149078 2000 6.327563706111373 2001 8.267900255182866 2002 6.910665398589795 2003 14.96980845967262 2004 8.24721863204793 2005 7.795487795487796 2006 8.125777857707178 2007 8.185829132056273 2008 9.045307468918327 2009 10.46824731588639 2010 10.630709807255695 2011 10.4067060907745 2012 9.438869056973724 2013 9.297907539710321 2014 9.374002700380508 2015 10.792873842775244 2016 8.78007788270237 2017 7.816082925222887 2018 7.9514422784690435 2019 7.60295358181748 2020 7.754849450647439 2021 8.352617350749732 2022 10.174342878274222