Year	%
2000	25.1
2001	24.9
2002	24.6
2003	23.9
2004	22.5
2005	22.5
2006	22.8
2007	23.1
2008	23.3
2009	23.2
2010	23.7
2011	23.9
2012	23.7
2013	22.7
2014	22
2015	22.6
2016	22.6
2017	22.2
2018	22
2019	21.9