Year % of expense 2009 5.8067137464837915 2010 5.238624683702612 2011 3.868901346368153 2012 5.067173911961976 2013 4.463696557353108 2014 4.778711841088324 2015 6.538605977299825 2016 7.819554707451614 2017 7.510394311774306 2018 9.693393338133875 2019 7.964362305424279 2020 7.661331411867749 2021 8.761468688399106 2022 9.953266811229824