Year	% of expense
2009	29.324859429456367
2010	33.194579514574144
2011	30.45145624460841
2012	32.37984879243625
2013	33.08420292981552
2014	23.70176288030769
2015	22.891634322627425
2016	20.691691540185268
2017	26.546018782183783
2018	32.62443765324551
2019	24.710156796024595
2020	25.6676269864704
2021	20.32871459984855
2022	17.8618485733709