Year % of revenue 2006 75.7596744829422 2007 79.51991877067877 2008 77.43505690272617 2009 61.75567651567297 2010 71.52968111998742 2011 75.21566469698989 2012 68.72077636110504 2013 65.94963826194422 2014 65.71580789204191 2015 56.545102286591074 2016 62.0230894404205 2017 65.61505238519496 2018 68.8398309017465 2019 50.003043268780175 2020 44.2683761843929 2021 64.93106980645571 2022 75.0623145436397