Year	% of expense
1990	24.038502072648072
1991	25.26466902805048
1992	20.034173589872054
1993	16.785829536404627
1994	16.66397293055896
1995	17.243447040393363
1996	16.40103699755288
1997	16.412139957471485
1998	15.014754882847118
1999	15.078509106382262
2000	14.694699172444645
2001	14.238718819744228
2002	11.344743435289374
2003	11.67036691354494
2004	11.506017531149032
2014	12.872710756605246
2015	13.168382156665565
2016	12.432860799694428
2017	12.750837971216114
2018	12.067359698856023
2019	11.62335383470766
2020	10.071122173040113
2021	10.48704810816377
2022	11.446763553872568