Year	% of expense
2000	17.482517482517483
2001	22.486605116327283
2002	18.297672261045044
2003	27.745406265209965
2006	12.823992655865288
2007	12.48527679623086
2008	16.284154283931738
2009	17.48630885826602
2010	15.105565878078512
2011	8.666307415687175
2012	10.744802977980278
2013	9.705730131254729
2014	16.331022839225938
2015	9.966249862022961
2016	3.9273153575615476
2017	3.6024733399050093
2018	3.0287866866369386
2019	4.211470446056553
2020	14.097967309866242