Year % of revenue 1993 0.015363933166890725 1994 0.46086412022542267 2004 2.977686655892516 2005 2.425594959410472 2006 2.127329157171074 2007 1.9484475916432265 2008 1.7893969771591804 2009 3.4509259378661032 2010 5.398310710221757 2011 5.688636538018875 2012 6.373104004393368 2013 5.796226221956222 2014 5.3885969155140145 2015 5.12991637698323 2016 4.670808731970268 2017 4.0422419154868034 2018 3.227308390893074 2019 2.9658713016911613 2020 2.239414796275087 2021 1.4481420239098244 2022 1.035169947965337