Year	%
2006	15.8
2007	13.2
2008	12.6
2009	13.9
2010	15.1
2011	14.1
2012	14.9
2013	16
2014	14.9
2015	16.3
2016	15.7
2017	15.3
2018	14.1
2019	15.1
2020	13
2021	13.5