Year	% of expense
1990	10.50662816642604
1991	10.444122372397677
1992	10.339395128758639
1993	9.930872140087768
1994	9.89281498888806
1995	9.58419723687722
1996	9.232242584486626
1997	9.301519941107694
1998	9.193245778611631
1999	9.240426867545512
2000	10.366082693659767
2001	9.79622141076048
2002	10.823465766265745
2003	10.867259921704473
2004	10.907750677506774
2005	10.696145330549646
2006	11.146166886419289
2007	11.124936942996468
2008	11.298652668169197
2009	11.826356400753388
2010	11.20990061642974
2011	11.815268019262652
2012	11.528019470071637
2013	11.987187574039144
2014	11.590934096160193
2015	10.732260391972082
2016	10.41614941880149
2017	10.852122878050592
2018	10.831376209018327
2019	10.470604244104019
2020	7.08328801756518
2021	9.056267768815225
2022	10.264412590490062