Year	% of expense
1985	9.241114313160423
1986	13.907518531591952
1987	6.225741344511722
1988	7.559238261375199
1989	10.823095823095823
1993	19.721031846063354
1994	19.733447979363714
1995	22.078151186380875
1996	28.501476760453908
1997	25.670740272510184
1998	25.32537960954447
1999	26.32219667252807
2000	21.767540096363277
2005	9.28645694815263
2006	11.61834475487612
2007	17.95462906823478
2008	15.060428029976569
2009	7.160707047752034
2010	15.892092840529825
2011	14.22501845233903
2012	10.218504151122138
2013	14.00947172274848
2014	13.451678466613764
2015	37.23000352433372
2016	17.25352183877975
2017	22.030626673668536
2018	24.530197076044598
2019	25.399863440391286
2020	36.36134136020207