Year	% of expense
2013	26.647297166089313
2014	26.47800826036084
2015	28.821258131918874
2016	28.21380432769351
2017	30.359860654452888
2018	28.733131171220588
2019	28.99449881027632
2020	30.914266162443067
2021	29.21847775615596
2022	28.582288907406113