Year	years
1998	8
1999	8
2000	8
2001	8
2002	9
2003	9
2004	9
2005	9
2006	12
2007	12
2008	12
2009	12
2010	12
2011	12
2012	12
2013	12
2014	12
2015	12
2016	12
2017	12
2018	12
2019	12
2020	12
2021	12
2022	12
2023	12