Year	%
2000	45
2001	44.7
2002	44.4
2003	44.2
2004	43.9
2005	43.6
2006	43.2
2007	42.8
2008	42.4
2009	42
2010	41.7
2011	41.5
2012	41.3
2013	41.2
2014	41.1
2015	41
2016	41
2017	40.9
2018	40.8
2019	40.8