Year % of expense 2003 10.490047183213946 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