Year	%
2000	21.5
2001	20.9
2002	20.9
2003	20.7
2004	21.6
2005	20.7
2006	20.9
2007	21.9
2008	21.9
2009	21.7
2010	21.8
2011	22.1
2012	22
2013	21.3
2014	21.5
2015	20.2
2016	19.9
2017	19.8
2018	19.9
2019	19.8