Year	% of expense
1995	34.33588317107093
1996	36.238170347003155
1997	36.86256916404965
1998	37.36271624434714
1999	36.697434505226
2000	34.31428753423785
2001	33.68488896701236
2002	35.35690083578044
2003	32.48196818496197
2004	33.55236757624399
2005	35.00986667950138
2006	34.88649940262844
2007	35.48920612813371
2008	33.50648351225519
2009	33.324263391121825
2010	32.94083014424492
2011	32.7694964231596
2012	33.700003363945235
2013	33.19244947247998
2014	33.166800487703334
2015	32.039239662072035
2016	32.68848940166353
2017	31.840000000000003
2018	30.64995943387722
2019	30.269906667787776
2020	35.456278752470745
2021	33.57515774638865
2022	35.29188029636842