Year % of profit 2006 33.2 2007 33.2 2008 33.8 2009 30.1 2010 29.2 2011 24.6 2012 21.8 2013 21.8 2014 21.8 2015 21.8 2016 22.2 2017 22.1 2018 22.2 2019 22.2