Year % of revenue 2008 1.410062259650848 2009 2.1614883139955507 2010 2.4803851083117125 2011 2.971583120127483 2012 3.4543203349981217 2013 3.0424904024444386 2014 3.023897179628732 2015 4.325927399641893 2016 4.990652984562533 2017 4.736515601517701 2018 4.761195014507715 2019 4.66280679918396 2020 4.867363520270771 2021 4.981860953831351 2022 3.762697555174335