Year % of revenue 2011 0.00887635235520561 2012 0.007910035251010451 2013 0.21430085624850054 2014 0.25542782056401425 2015 0.2001580922704306 2016 0.18650820585134814 2017 0.07848343605653023 2018 0.03966593221550492 2019 0.05252274915976059 2020 0.015413194172138062 2021 0.016061119301962287 2022 0.01100812959677033