Year	% of expense
1998	5.820918492982024
1999	5.892582169595921
2001	10.520283370577422
2002	12.782453912955683
2003	11.580448122647132
2004	10.002341242474431
2005	7.03823953397849
2006	7.643152448743903
2007	7.939185276320429
2008	5.293568690294742
2009	6.682965921391714
2010	4.8980640053684
2011	5.136323786437598
2012	7.6011118024237
2013	4.053756355232597
2014	4.7753558281960515
2015	10.374872940698799
2016	11.49267534051205
2017	12.7595794030854
2018	11.414293818338345
2019	9.45151632323909
2020	9.495201401660754
2021	7.829025703196302
2022	8.119347718482297