Year	% of expense
1993	15.626183991364458
1994	12.60830331033266
1995	18.834607168575907
1996	26.203323866624594
1997	28.874544529829375
1998	26.298941147500614
1999	26.274624329634154
2000	17.48163232248435
2001	20.64997715573806
2002	15.48516039528385
2003	15.453038977097927
2004	35.58211169898131
2005	33.3449334342212
2006	32.03155162982382
2007	29.534038153397734
2008	38.93322571860605
2009	28.156445636657885
2010	26.229781748281262
2011	26.015767669113337
2012	27.842958427973326
2013	26.5125973799626
2014	26.00731483616968
2015	16.545777432859218
2016	17.164929577726546
2017	13.158897131948674
2018	15.184888885540213
2019	15.764379190112027
2020	27.240173037540664
2021	20.05871346798705
2022	24.332812707249012