Year	%
2000	47.1
2001	46.7
2002	46.3
2003	45.9
2004	45.5
2005	45.1
2006	44.6
2007	44.1
2008	43.5
2009	43
2010	42.4
2011	41.9
2012	41.3
2013	40.8
2014	40.3
2015	39.9
2016	39.4
2017	39
2018	38.6
2019	38.2