Year	%
2000	29.2
2001	29.3
2002	29.6
2003	29.6
2004	29.9
2005	30
2006	30.2
2007	30.6
2008	30.9
2009	31
2010	30.9
2011	30.9
2012	30.8
2013	30.7
2014	30.5
2015	30.3
2016	30
2017	29.7
2018	29.4
2019	29.1