Year	%
2000	61.6
2001	61.5
2002	61.4
2003	61.2
2004	61
2005	60.8
2006	60.6
2007	60.4
2008	60.1
2009	59.9
2010	59.7
2011	59.5
2012	59.4
2013	59.3
2014	59.2
2015	59.2
2016	59.2
2017	59.1
2018	59.1
2019	59