Year % of revenue 2002 1.9027279723965014 2003 2.7151583421267476 2004 2.371152579401384 2005 2.1082167163849457 2006 1.9300362768232604 2007 1.772985973095894 2008 2.4677231225413703 2009 1.9728066633862704 2010 1.928208507428265 2011 1.5153446711035148 2012 1.4631773267466368 2013 1.619257645234908 2014 1.8707981199364054 2015 1.789346685459965 2016 2.0418291386033323 2017 4.2207910018387835 2018 1.5370262104342216 2019 1.5024383376850885 2020 1.743572748581287 2021 1.7910330462094262 2022 1.8058312579727749