Year	%
1997	9.6
1998	9.6
1999	10.4
2000	10.4
2001	10.4
2002	10.4
2003	12
2004	12
2005	12
2006	12
2007	12
2008	12.4
2009	12.4
2010	12.4
2011	12.4
2012	12
2013	12
2014	12
2015	12.4
2016	13.2
2017	13.2
2018	13.2
2019	13.2
2020	11.2
2021	11.2
2022	11.2
2023	10.8