Year	% of expense
1990	1.2637448169480483
1991	6.711146633776645
1992	5.466361645388367
1993	5.2070763661437685
1994	4.055114736679748
1995	20.13117455172689
1996	3.709991653879003
1997	3.4437639891493994
1998	4.06820687048508
1999	3.873197960261464
2000	4.429464267905906
2001	4.399497162775053
2002	4.382781232222877
2003	4.378183622674287
2004	4.260078541943455
2005	4.218471844557272
2006	4.178849134426897
2007	4.361620499897532
2008	4.994950430648816
2009	4.713742813251338
2010	8.04029364910505
2011	4.0887800130827054
2012	4.081041310038428
2013	4.198285270374554
2014	4.165076672083516
2015	4.113055847352242
2016	4.2221815043498
2017	5.175206720717667
2018	4.488518372301892
2019	4.544361867681608
2020	4.33914048932046
2021	5.5088049097581315
2022	7.925000826175231