Year % of expense 2000 10.270901467331003 2001 9.524269705485567 2002 9.550419844952156 2003 10.21683528371332 2004 9.566684252908672 2005 11.395264444348179 2006 12.157161467863808 2007 11.950727577680134 2008 10.852844334739531 2009 10.861439885683298 2010 11.07504145031216 2011 9.297501192724123 2012 9.078784204936111 2013 9.752452699818628 2014 8.972116877247451 2015 8.742444921037238 2016 8.301109535005732 2017 8.825251503699366