Year	% of expense
1982	19.069997526589166
1983	18.823529411764707
1984	16.64993153811045
1985	19.011524479851495
1986	18.01543990416611
1987	8.826898456977293
1988	3.4325086125900404
1989	6.973860936047112
1990	44.07603890362511
1991	41.169796557120506
1992	38.75135543653271
1993	37.80444988079665
1994	37.606120951682215
1995	40.8378268158956
1996	44.887568174817446
1998	49.0302248849865
1999	53.82415342722064
2002	55.03917941208526
2003	56.09970219806255
2004	63.31541656212018
2008	68.44225718047412
2009	60.41133018077309
2010	63.01672161520635
2011	66.12262363069289
2012	67.10792366991028
2013	65.52469135802468
2014	63.47408244922427
2015	54.648529848808614
2016	51.19596493047567
2017	50.359723112731245
2018	48.692070883778726
2019	49.599819848207446
2020	48.51689384816362
2021	46.77677598881004
2022	17.799185614120045