Year	%
2000	33.5
2001	33.6
2002	33.7
2003	33.7
2004	33.5
2005	33.3
2006	33.1
2007	32.7
2008	32.4
2009	32
2010	31.8
2011	31.5
2012	31.3
2013	31.1
2014	30.9
2015	30.7
2016	30.4
2017	30.1
2018	29.8
2019	29.4