Year	% of expense
2012	22.58985555488225
2014	23.441175563486567
2015	23.79146692762236
2016	27.902824577345857
2017	23.865434612033688
2018	21.859264140376123
2019	23.478038048754026
2020	28.648242550877427
2021	28.03871796347881