Year	%
2000	29
2001	28.7
2002	28.3
2003	28
2004	27.6
2005	26.9
2006	26.2
2007	25.7
2008	25.2
2009	24.7
2010	24.1
2011	23.7
2012	23.4
2013	23.2
2014	22.9
2015	22.7
2016	22.4
2017	22.3
2018	22.2
2019	22.1