Year	% of expense
2009	29.109174356776457
2010	30.956969160030205
2011	31.38399239793653
2012	27.45290880137318
2013	31.08839452059317
2014	30.47867314690989
2015	32.01665979710936
2016	29.52924582533385
2017	30.342552787495148
2018	23.705201426600183
2019	25.76907287974889
2020	32.561299805409035
2021	27.17437399804726
2022	30.941738837563705