Year	%
2000	61.1
2001	61
2002	60.9
2003	60.8
2004	60.7
2005	60.5
2006	60.3
2007	60.1
2008	59.8
2009	59.5
2010	59.2
2011	58.9
2012	58.5
2013	58.1
2014	57.7
2015	57.3
2016	56.8
2017	56.2
2018	55.7
2019	55.1