Year	%
1970	11.2
1975	10.7
1979	11.2
1984	11.5
1990	11
1996	12.2
1997	12.2
1998	11.7
1999	11.5
2000	11.7
2001	11.5
2002	10.5
2003	8.9
2004	8.8
2005	8.6
2006	9.3
2007	9.2
2008	9.8
2009	11.1
2010	10.3
2011	9.9
2012	10.1
2013	9.8
2014	10.1
2015	10.8
2016	10.4
2017	10.1
2018	10
2019	11.6
2020	11.1
2021	12