Year	% of expense
1996	14.329396878954029
1997	13.419524625088766
1998	14.54820352365553
1999	14.207249436433248
2000	15.386680623147821
2001	14.576583241020522
2002	14.275590202418389
2003	14.287456139162478
2004	12.195503333966247
2005	12.069772521608888
2006	11.81657947929664
2007	10.709769014099026
2008	8.493640418711166
2009	9.205725870919752
2010	10.430519282189112
2011	9.846094530283914
2012	9.58804784718464
2013	9.899957963096071
2014	10.371694527372107
2015	11.280094851408563
2016	12.639650605007876
2017	12.829700392581127
2018	13.25178322234459
2019	12.542315251730848
2020	13.165062870501359
2021	14.246473839613497
2022	12.84762109339734