Year	% of expense
2004	0.8347933628774605
2005	2.6426141308647835
2006	6.190800470500836
2007	7.841282709543755
2008	8.983120041179289
2009	11.947798295454545
2010	11.057856898322491
2011	11.342374116205521
2012	15.262722627521635
2013	13.534212178279976
2014	15.579718851375707
2015	12.834666248497204
2016	13.942660878691026
2017	14.09570636121317
2018	11.437890276538806
2019	12.439950474618241
2020	11.500141934322489
2021	13.260611637085642
2022	14.883838689614556