Year	% of expense
2012	45.31603658523461
2013	43.11128202376943
2014	45.675195167057424
2015	44.015811403145975
2016	39.42182012826233
2017	37.01664471349627
2018	42.71515044850691
2019	44.86011178790646
2020	42.53939524770365
2021	41.485425051543274