Year	%
2000	21
2001	22
2002	21.8
2003	19.4
2004	20.4
2005	20.9
2006	20.9
2007	22.5
2008	22.5
2009	22.3
2010	21.4
2011	21.2
2012	22.4
2013	22
2014	22.1
2015	21.5
2016	21.5
2017	22.1
2018	21.8
2019	21.7