Year	% of expense
2003	11.50625935386439
2004	11.5613262515453
2006	9.783031763231154
2007	8.496442395356551
2008	7.697607380460603
2009	7.229323150070825
2010	6.883331395942077
2011	6.477433848352892
2012	6.530256589963102
2013	7.62914954612603
2014	7.417549756832541
2015	6.811219853553287
2016	7.723941899318982
2017	8.470574798693253
2018	10.262571770488865
2019	10.61226286619316
2020	8.963373688366435
2021	9.867361213809627