Year	%
2000	44.1
2001	43.9
2002	43.7
2003	43.4
2004	43.2
2005	42.9
2006	42.5
2007	42.1
2008	41.7
2009	41.3
2010	40.9
2011	40.7
2012	40.5
2013	40.3
2014	40.3
2015	40.3
2016	40.2
2017	40.2
2018	40.1
2019	40