Year	%
2000	34
2001	33.6
2002	33.3
2003	32.9
2004	32.5
2005	32
2006	31.5
2007	30.9
2008	30.4
2009	29.9
2010	29.7
2011	29.5
2012	29.4
2013	29.5
2014	29.7
2015	29.9
2016	30.1
2017	30.3
2018	30.5
2019	30.8