Year	%
2000	36.7
2001	36.6
2002	36.5
2003	36.5
2004	36.4
2005	36.3
2006	36.2
2007	36.1
2008	35.9
2009	35.7
2010	35.6
2011	35.6
2012	35.5
2013	35.5
2014	35.4
2015	35.4
2016	35.5
2017	35.4
2018	35.4
2019	35.3