Year	% of expense
1991	4.8205844199197445
1992	4.961596616214751
1993	3.857948098739969
1994	2.3567343502294147
1995	1.2262902635985673
1996	1.4523240765356544
1997	2.020933461485641
1998	1.591253800847451
1999	6.53185295964999
2000	5.890368191831756
2001	6.978531241115809
2002	7.956819872721943
2003	7.584373633029375
2004	8.058514867228494
2005	7.4449942687802295
2006	7.444924966826595
2007	6.77172603368354
2008	16.726947216546936
2009	11.286548122417507
2010	12.595362429135218
2011	9.810434474234421
2012	9.335656343479089
2013	8.441392087136364
2014	6.823113944388017
2015	5.963350525143283
2016	4.311617889485698
2017	5.669258378593379
2018	4.71132417141044
2019	6.177724233102058
2020	6.32617664660773
2021	7.733586551165107
2022	8.097649232147079