Year % of expense 2007 5.395659561321524 2008 6.044199552364515 2009 6.361382485199025 2010 6.753874659150294 2011 6.628589714652115 2012 5.353302107097123 2013 4.541484451157546 2014 5.940606212608259 2015 5.825554213807045 2016 5.610134820507643 2017 5.829219405536518 2018 6.7387721149315825 2019 6.424657514684687 2020 6.629120114301232 2021 6.549892590369431 2022 8.119347718482297