Year	% of expense
2004	53.465691264188294
2008	39.47418785910473
2009	27.38744553045065
2010	24.7183383931604
2011	29.731357456907396
2012	48.82556364156394
2014	69.49666058710726
2015	60.741119600538426
2016	50.40828471704587
2017	47.8910066085624
2018	49.11389441329451
2019	50.287958317550384
2020	38.68037003218483
2021	49.902426544037226