Year	years
1998	7
1999	7
2000	7
2001	8
2002	8
2003	7.5
2004	8
2005	8
2006	8
2007	8
2008	8
2009	9
2010	8.5
2011	8.5
2012	8.5
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