Year	% of expense
2006	57.21637663336742
2007	66.5901367809826
2008	72.458784315372
2009	71.72411867863757
2010	74.70011212606018
2011	75.73347927407539
2012	68.10745579361644
2013	67.0283936941842
2014	66.71606897908893
2015	61.039251141681795
2016	58.77513498593772
2017	54.778868898314585