Year	%
2004	34.7
2005	34.6
2006	34.4
2007	34.4
2008	34
2009	34.7
2010	34.8
2011	34.8
2012	35.2
2013	35.7
2014	35.4
2015	35.1
2016	34.7
2017	34.4
2018	34.9
2019	34.6
2020	34.4
2021	34.6