Year	% of expense
1990	4.973273189495536
1991	4.967005339792059
1992	2.652113133058232
1993	2.767058665558774
1994	2.594564873569503
1995	2.380646341682976
1996	2.638695373459965
1997	2.480871294796943
1998	2.7208008542849287
1999	2.8684495813321793
2000	2.978341194066684
2001	6.431739633671601
2002	6.350469581833566
2003	6.254855090714578
2004	6.3214292011423066
2005	6.430142756980779
2006	6.033535084348877
2007	6.262919750839244
2008	8.63120450370732
2009	7.7241258999017335
2010	6.456054881190497
2011	6.353136908439084
2012	6.208254472199943
2013	5.88100347021999
2014	5.738432400854348
2015	5.621756111061352
2016	5.510899974185623
2017	5.611120516741379
2018	5.415236789246107
2019	5.542636535240057
2020	6.439517555763906
2021	8.90873430114673
2022	5.701474842321115