Year	% of expense
2009	20.908960322155757
2010	19.23282250387322
2011	19.847728242133588
2012	20.651815728239473
2013	18.201724057460332
2014	21.68980899967017
2015	21.021839938577656
2016	19.164673090146294
2017	20.35715633529277
2018	17.037604814271255
2019	17.666446080844445
2020	17.229610422769415
2021	17.492537711977846
2022	15.558362372038417