Year	%
2000	39.6
2001	37.1
2002	40.2
2003	38.2
2004	38.2
2005	34.9
2006	36.6
2007	36.9
2008	38.9
2009	41
2010	37
2011	36.5
2012	35.5
2013	35.1
2014	35
2015	35.5
2016	37
2017	35.4
2018	35.3
2019	35.5