Year	%
1992	11.7
1993	10.4
1996	9.8
2002	9.5
2004	9
2005	9.3
2006	9.3
2007	9.7
2008	9.8
2009	9.6
2010	9.4
2011	9.3
2012	9.6
2013	9.4
2014	9.7
2015	9.7
2016	10
2017	10.2
2018	10.2
2019	10.1
2020	9.8
2021	9.7