Year	% of expense
1992	55.4126473740621
1993	54.8983702618568
1994	54.66685608751243
2002	48.91769212498137
2003	49.17688451628016
2004	48.284740941814555
2005	47.51047449990756
2006	47.95140325253483
2007	48.80681718742061
2008	47.86265604291337
2009	48.254385858647765
2010	48.84414338115045
2011	46.348617615735755
2012	47.266662132454435
2013	38.104589540902964
2014	44.11069851362938
2015	44.777647948394794
2016	45.147731079184645
2017	46.54130866807813
2018	46.425073864255936
2019	46.56906409408517
2020	49.748703865609265
2021	46.53386521217776
2022	47.204245150079636