Year	% of expense
2008	36.25028145019879
2009	35.87020059690983
2010	35.977748502436775
2011	35.99583669852559
2012	35.5887568364776
2013	36.123078081923296
2014	35.0874112876145
2015	35.29706296717186
2016	35.263089018099315
2017	33.92117338625831
2018	33.97839183431766
2019	33.88551451841561
2020	38.711739038764016
2021	37.00333275132952