Year	%
2000	56.9
2001	56.5
2002	56.2
2003	55.8
2004	55.4
2005	55
2006	54.5
2007	54
2008	53.5
2009	53
2010	52.5
2011	51.9
2012	51.4
2013	50.9
2014	50.4
2015	49.9
2016	49.4
2017	49
2018	48.5
2019	48.1