Year	%
2000	17.8
2001	18.1
2002	17.3
2003	19
2004	20
2005	19.6
2006	18.2
2007	16.7
2008	16.4
2009	20.9
2010	20.5
2011	20.4
2012	19.1
2013	19.3
2014	19.6
2015	19.6
2016	19.9
2017	20.3
2018	20.7
2019	21.5