Year	%
1987	11.7
1994	11.5
1995	11.5
1996	11.9
2000	12.5
2002	12.8
2003	12.5
2004	12.4
2005	12.4
2006	12.4
2007	12.8
2008	13
2009	12.6
2010	12.7
2011	12.7
2012	12.5
2013	12.5
2014	12.8
2015	12.9
2016	12.6
2017	13
2018	13.1
2019	13
2020	13.3
2021	13.1