Year % of profit 2005 25.8 2006 25.8 2007 25.8 2008 22.8 2009 22.3 2010 22.3 2011 21.8 2012 21.8 2013 21.2 2014 20.7 2015 21.3 2016 20.7 2017 20.7 2018 20.7 2019 20.7