Year	% of expense
1993	63.60184431787361
1994	56.68602439581062
1995	29.235682634307715
1996	30.21876936593122
1997	21.739454914035196
1998	30.39861289352649
1999	35.84021811402763
2000	33.20673385640073
2001	34.78245777343796
2002	34.09597670368848
2003	34.725221443376185
2004	34.07797179606983
2005	35.1980140595598
2006	34.56310077511055
2007	37.40223845498023
2008	38.892563431156695
2009	43.039045612557366
2010	39.35001788887781
2011	34.68140174940324
2012	38.21298059119678
2013	37.21512659668836
2014	36.97340676985545
2015	37.770362978211594
2016	38.42000346420997
2017	40.02702576972926
2018	41.544031957121575
2019	41.93793831444208
2020	46.18242791221976
2021	44.82230253628946
2022	43.76615018959454