Year	%
2000	56
2001	55.7
2002	55.4
2003	54.9
2004	54.6
2005	54.5
2006	54
2007	53.9
2008	53.7
2009	53.4
2010	53
2011	52.8
2012	52.4
2013	52.3
2014	52
2015	51.7
2016	51.5
2017	51.3
2018	51
2019	50.8