Year	%
2000	37.9
2001	40.1
2002	42.7
2003	44.5
2004	45.7
2005	46.5
2006	46.8
2007	47.9
2008	47.8
2009	47.3
2010	45.8
2011	43.9
2012	43.4
2013	42
2014	39.8
2015	38
2016	37.1
2017	36
2018	35.1
2019	35.2