Year	%
2000	22.8
2001	22.7
2002	22.6
2003	22.5
2004	22.4
2005	22.3
2006	22.2
2007	22
2008	21.6
2009	21.8
2010	21.8
2011	21.8
2012	21.8
2013	21.7
2014	21.6
2015	21.5
2016	21.4
2017	21.4
2018	21.1
2019	21