Year	%
2000	31.7
2001	33.2
2002	33.8
2003	34.6
2004	34.3
2005	33.9
2006	34.4
2007	34.3
2008	34.4
2009	34.9
2010	34.7
2011	34.3
2012	35
2013	33.8
2014	34.1
2015	35.2
2016	34.4
2017	33
2018	33.1
2019	32.7