Year % of expense 2003 10.490047183213946 2004 7.467730397438597 2005 5.299883701611564 2006 7.643152448743903 2007 7.939185276320429 2008 9.801964443287188 2009 8.374941319048288 2010 9.073020772630112 2011 9.434131068764405 2012 8.978909633982955 2013 9.274083429913077 2014 8.713837298340595 2015 9.325192100743557 2016 8.107315980199676 2017 8.895367001124892 2018 8.650624540903047 2019 7.368804945238453 2020 8.348527071194365 2021 7.416299937283412 2022 8.119347718482297