Year % of revenue 2011 3.5194918847057046 2012 4.598551209174971 2013 1.059405298993266 2014 0.07978591498513488 2015 0.058209656333451126 2016 0.06341366473680239 2017 0.12167819985995061 2018 0.1851394471653766 2019 0.6681353044350684 2021 0.7850765015741831 2022 0.849321564789015