Year	% of expense
1990	8.654535235017214
1991	11.051473562696714
1992	9.802660604655685
1993	7.608364197256738
1994	8.321037731422345
1995	10.201654511429421
1996	11.213384052528287
1997	13.035103080474409
1998	14.7114600687675
1999	17.27453119931244
2000	20.104014030188317
2001	22.274349017366106
2002	34.28493388546651
2003	30.008394862178832
2004	26.314253789368408
2014	7.757889165266385
2015	7.374210737495614
2016	11.39009416026078
2017	9.419814018022436
2018	12.869746280293104
2019	15.796801238490657
2020	7.502647266089964
2021	6.5236747286881265
2022	7.759549398953626