Year % of expense 2002 18.291619852001084 2003 17.994444103651645 2004 17.341895340194178 2005 15.9896670260155 2006 9.764740993728667 2007 11.044776665897748 2008 8.829739367495014 2009 8.701547036691318 2010 7.652260962507876 2011 8.303693614886297 2012 7.641753891558767 2013 5.8658178109471 2014 5.856595761551399 2015 6.970763400108283