Year	% of expense
1995	17.566649833701916
1996	10.383098885962145
1998	8.953295931382868
2002	14.754271479411358
2003	11.445871896078721
2004	11.716824387866442
2011	9.164343987352916
2012	8.960246563075478
2013	10.07973616302297
2014	7.382408438489409
2015	8.324933054686976
2016	9.318367749249832
2017	9.046592521454983
2018	8.957129926974485
2019	9.344304550330428
2020	9.005221572880473
2021	9.391307773110974