Year	% of expense
2008	6.690467722017085
2009	6.384380359043794
2010	6.478525824704825
2011	6.157213419935392
2012	6.050132936504557
2013	5.7848037781084445
2014	5.80262662160235
2015	5.895067782179883
2016	5.493271535344631
2017	5.289371703187431
2018	5.201086441355725
2019	4.816447997589146
2020	5.974824850691716
2021	5.946872624477808