Year % of expense 2004 25.724903090141567 2005 29.913021710563083 2006 30.80838991242872 2007 29.884329072824045 2008 36.82065052866593 2009 34.31710428602069 2010 31.580021663886647 2011 36.05837996977788 2012 39.86635961266954 2014 32.31466375445256