Year	%
2000	33.8
2001	34
2002	33.5
2003	33.2
2004	33.2
2005	33.2
2006	33.7
2007	33.5
2008	33.5
2009	34.2
2010	33.9
2011	33.9
2012	34.2
2013	34
2014	33.7
2015	33.8
2016	33.6
2017	33.5
2018	33.5
2019	33.5