Year	% of expense
1996	2.5793291469949473
1997	1.7559346357655208
1998	0.7305568409308216
1999	17.356330890082752
2000	14.518093712778487
2001	14.162040606858946
2002	13.703062966939564
2003	14.596505888183357
2004	15.108311424688495
2005	17.95418220564731
2006	20.66965666563563
2007	21.754353383345958
2008	31.43868311676262
2009	32.79541116705698
2010	35.701531138222656
2011	17.25240785755483
2012	15.363397463553403
2013	18.308214468585422
2014	19.64684788782191
2015	21.302203739336935
2016	21.356731843748474
2017	20.844963206674475
2018	21.83093558796432
2019	19.919185762151965
2020	15.542722905190587
2021	16.71103522248167
2022	12.445968368110288