Year	%
2000	40.9
2001	40.8
2002	40.8
2003	40.9
2004	40.9
2005	41
2006	41
2007	40.9
2008	40.8
2009	40.7
2010	40.7
2011	40.6
2012	40.5
2013	40.7
2014	40.6
2015	40.3
2016	40.1
2017	39.9
2018	39.7
2019	39.4