Year	%
2000	55.7
2001	55.8
2002	55.9
2003	55.9
2004	56
2005	56
2006	55.9
2007	55.9
2008	55.7
2009	55.6
2010	55.4
2011	55.3
2012	55.1
2013	55
2014	54.8
2015	54.6
2016	54.4
2017	54.2
2018	54
2019	53.7