Year	% of expense
1993	57.407614529271044
1994	56.68602439581062
1995	41.443957565250656
1996	41.223896940521755
1997	45.18176691862805
1998	43.562916582667114
1999	44.46746295136925
2000	44.275296231906154
2001	45.46062937065496
2002	46.97789931912044
2003	45.84826007246187
2004	47.01508535580904
2005	45.832986020877975
2006	45.930053544366004
2007	47.851414344518325
2008	47.86265604291337
2009	48.254385858647765
2010	48.84414338115045
2011	48.531170307295426
2012	48.55351542015025
2013	50.131549011408374
2014	49.642167866734766
2015	47.59857648790043
2016	47.49614186506133
2017	46.54130866807813
2018	45.74359846442208
2019	45.48623912840713
2020	47.49870930819938
2021	46.53386521217776
2022	49.95767976696222