Year % of revenue 1996 9.311392289034533 1997 10.331890007227932 1998 14.527662532865776 1999 14.44826335526298 2002 11.577699547381277 2003 8.61009819480718 2006 5.752087420936908 2007 3.911386696631019 2008 4.799223004358661 2009 4.515480448498009 2010 4.71268629415266 2011 3.318777802213272 2012 4.722005597968546 2013 5.3451548266205675 2014 6.943998848166133 2015 6.291372177228532 2016 9.670424215185333 2017 8.853967564538635 2018 10.712352004199161 2019 9.555309553370153 2020 10.320037751994935 2021 7.3209933259318545 2022 12.945974704536015