Year	% of expense
2007	15.504128572434334
2008	14.681139027119528
2009	14.802727296532918
2010	14.701925388125826
2011	14.39840260761393
2012	15.685809033065754
2013	15.495750620843781
2014	14.786097982625567
2015	15.287578133457263
2016	13.964604302819254
2017	14.724713574554038
2018	14.285578760603123
2019	13.533507980508453
2020	13.502798432651945
2021	14.798148367893546