Year % of revenue 2011 0.37061257068890596 2012 0.5305261431423127 2014 2.25008465638701 2015 2.3325383509843967 2016 4.033116028174156 2017 5.7794041605277116 2018 8.798145618371493 2019 6.461241766163401 2020 7.6775663109655845 2021 8.230942948104504