Year	% of expense
1995	38.855572213893055
2002	29.06557027574991
2003	35.95287391101822
2004	33.25704189266689
2005	34.44632547788701
2006	32.36130252791145
2007	33.51397653560185
2008	31.19244432973181
2009	32.3869630616578
2010	33.515790477748006
2011	33.953548693493005
2012	35.494101388217345
2013	39.96515456709584
2014	41.162799141108714
2015	42.21417195289863
2016	42.02645083119999
2017	41.32057228666298
2018	45.256157984822295
2019	40.06500715492896
2020	41.869172885841266
2021	39.17257740309593
2022	36.81870508727359