Year	%
2000	26.5
2001	26.7
2002	27.2
2003	26.8
2004	25.7
2005	25.5
2006	24.8
2007	24.1
2008	23.7
2009	23.7
2010	23.1
2011	22.1
2012	22
2013	21.4
2014	21.7
2015	21.7
2016	21.6
2017	21.5
2018	21.7
2019	21