Year	%
1996	26.3
2001	27.1
2002	26.8
2003	25.8
2004	25.1
2005	29.7
2006	24.9
2007	24.6
2008	23.6
2009	23.1
2010	23.1
2011	23
2012	22.9
2013	22.5
2014	22.6
2015	22.6
2016	22.7
2017	23
2018	23.4
2019	23.6
2020	24.2
2021	24.8