Year % of expense 2005 1.624470773938255 2006 1.5321855878016466 2007 1.286841836038921 2008 1.18610288070247 2009 1.1397593741503071 2010 1.0887467017181247 2011 1.4378643979386092 2012 1.7688886591065107 2013 1.7936821878728895 2014 1.9614890924581636 2015 2.2705990115119294 2016 2.190187031034354 2017 1.939986628243244 2018 1.9195572035758741 2019 1.8091141773568749 2020 1.775893260183632 2021 1.6033265499586526 2022 1.5907098197283187