Year	% of expense
2010	35.736253728928254
2012	36.08939144238621
2013	37.10443392459204
2014	38.3600545871913
2015	36.75759026095814
2016	36.65405380223012
2017	38.39949816291782
2018	36.65140083393944
2019	39.90478026395445
2020	38.78660154727716
2021	35.701538686962834