Year	%
2000	61.6
2001	61.4
2002	61.3
2003	61.2
2004	61
2005	60.8
2006	60.6
2007	60.4
2008	60.1
2009	59.8
2010	59.5
2011	59.2
2012	59
2013	58.8
2014	58.6
2015	58.5
2016	58.4
2017	58.3
2018	58.2
2019	58.1