Year % of revenue 1995 30.150224018272866 2001 20.571334965574103 2002 19.767199974906788 2003 16.86784277313525 2004 13.286214035839222 2005 12.220535467844327 2006 8.831367087590557 2007 9.672913514142707 2008 9.05015647466802 2009 7.806612190792249 2010 9.256630592180475 2011 14.326132695599899 2012 10.014187995236274 2013 8.028641277531063 2014 4.806658733386415 2015 8.321598320937998 2016 9.845880055053293 2017 9.701796287607927 2018 10.496907423999856 2019 11.55769992226501 2020 14.470951296779742 2021 14.811339870417376 2022 17.44391055282066