Year	%
1979	13.1
1989	11.6
1991	11.5
1995	11.6
1997	11.1
1998	11.5
1999	11.5
2000	11.4
2001	11.6
2002	11.4
2003	11.5
2004	11.7
2005	11.9
2006	11.8
2007	12.4
2008	12.4
2009	12.4
2010	12.6
2011	12.6
2012	12.7
2013	12.7
2014	13.1
2015	12.8
2016	12.9
2017	13.3
2018	13.4
2019	13.2
2021	12.5
2023	13.3