Year	% of expense
1985	5.6518206175605075
1986	4.468074868883223
1987	4.161080746622659
1988	4.238783496584659
1989	3.8030188626964674
1990	68.57393982084649
1991	68.69138724232523
1992	69.60835050237745
1993	68.6284422896601
1994	69.25551508888333
2012	71.6825996599282
2013	76.300410158337
2014	76.73749231013338
2015	77.89159841619792
2016	78.5370876292198
2017	79.1113368582305
2018	79.08028336213134
2019	79.83895804564014
2020	82.74311337490884
2021	81.04511311297041
2022	80.43644685345605