Year	years
1998	6.5
1999	6.5
2000	6.5
2001	7
2002	7
2003	7
2004	8
2005	8
2006	8
2007	8
2008	8.5
2009	8
2010	8
2011	8
2012	8
2013	8.5
2014	8.5
2015	8.5
2016	8.5
2017	8.5
2018	8.5
2019	8.5
2020	8.5
2021	8
2022	8
2023	8