Year % of revenue 2002 4.970933755136332 2003 4.465255284399032 2006 4.1010215815219295 2007 2.8099251346223975 2008 4.059392810993221 2009 3.2817380185946208 2010 3.5448263392058204 2011 3.318777802213272 2012 4.348374202716511 2013 5.131569475452839 2014 5.4335787376498175 2015 4.794203010914434 2016 5.482367385151073 2017 4.806842355438929 2018 7.757719792622664 2019 5.183886947072978 2020 4.4543089742907895 2021 4.805067791469128 2022 7.024439770887518