Year	%
2000	33.5
2001	33.2
2002	32.9
2003	32.8
2004	32.6
2005	32.4
2006	32.2
2007	32
2008	31.7
2009	31.5
2010	31.2
2011	31.1
2012	31
2013	30.9
2014	30.8
2015	30.7
2016	30.7
2017	30.6
2018	30.5
2019	30.5