Year	%
2000	44.4
2001	43.9
2002	43.4
2003	42.9
2004	42.4
2005	41.9
2006	41.4
2007	40.9
2008	40.3
2009	39.8
2010	39.3
2011	38.8
2012	38.3
2013	37.9
2014	37.6
2015	37.3
2016	37.1
2017	36.9
2018	36.7
2019	36.5