Year	%
2000	24.9
2001	25.1
2002	24.9
2003	25.4
2004	25.6
2005	25.4
2006	25.4
2007	25
2008	25
2009	25.1
2010	24.7
2011	24.3
2012	23.8
2013	23.3
2014	23
2015	22.5
2016	22.1
2017	21.9
2018	22.2
2019	22.2