Year	%
2000	34.7
2001	34.6
2002	34.8
2003	36.1
2004	33.8
2005	35
2006	34.6
2007	38.7
2008	40.6
2009	40.7
2010	40.4
2011	40.6
2012	40.4
2013	40.2
2014	40.3
2015	40
2016	39.5
2017	39.3
2018	39.7
2019	39.2