Year	%
2000	54
2001	54
2002	53.9
2003	53.8
2004	53.6
2005	53.5
2006	53.2
2007	53
2008	52.7
2009	52.4
2010	52.1
2011	51.7
2012	51.4
2013	51.1
2014	50.8
2015	50.5
2016	50.1
2017	49.8
2018	49.5
2019	49.1