Year	years
1998	7
1999	7
2000	7
2001	7.5
2002	8
2003	8
2004	8.5
2005	8
2006	9
2007	9
2008	9
2009	9
2010	8
2011	8
2012	8
2013	8
2014	8
2015	9
2016	9
2017	9
2018	9
2019	9
2020	9
2021	9
2022	9
2023	9