Year	% of expense
1996	56.042745013807064
1997	56.777241765588016
1998	56.72629034970254
1999	46.45866138186487
2000	53.54798042943061
2001	53.652766075411876
2002	52.56865552889401
2003	49.99943888137119
2004	49.70516214179815
2005	49.236370094121824
2006	45.32168264769564
2007	45.460459936775166
2008	34.00411546992158
2009	28.581817564708217
2010	27.53523198578663
2011	30.233393078735087
2012	31.74088289201546
2013	30.626545733488015
2014	29.928717253697894
2015	30.593031951304873
2016	30.83296353229383
2017	31.868335546398203
2018	31.823521370579904
2019	31.166508724624737
2020	26.600933286531834
2021	30.219510800533556
2022	23.953924282747096