Year	% of profit
2005	34.7
2006	34.6
2007	34.6
2008	34.2
2009	34.9
2010	36.1
2011	36.2
2012	35
2013	34.7
2014	33.5
2015	32
2016	30.9
2017	30.7
2018	30
2019	30.6