Year	% of expense
1986	1.2292028805562454
1987	5.099729509819014
1988	7.689317643732994
1989	4.8794444702206965
1990	25.688502673796794
1991	52.15043486253193
1992	29.236968018131453
1993	30.92388560567814
1994	27.50197858957804
1995	40.39252630924384
1996	42.42061626175943
1997	43.70714050483041
1998	43.497294913668675
1999	31.40074211502783
2000	32.75055905671885
2001	32.33535158426507
2002	34.642131165079704
2003	32.06162735867583
2004	33.11899659061162
2005	33.47036060073779
2006	33.248001263386534
2007	30.426155003280574
2008	31.038607312187455
2009	30.04460758574324
2010	31.757582371985464
2011	33.46854404010538
2012	32.22972100065246
2013	33.06430671693972
2014	31.40384661637854
2015	32.96358595076006
2016	34.31690746917996
2017	34.167208735031195
2018	28.94885365154451
2019	29.123544536420702
2020	35.87133844042438
2021	38.31078661655688
2022	40.72421174516535