Year	years
1999	4
2000	4
2001	4
2002	4
2003	3.5
2004	3.5
2005	3.5
2006	3.5
2007	3.5
2008	3.5
2009	3.5
2010	4
2011	4
2012	4
2013	6
2014	6
2015	6
2016	6
2017	6
2018	6
2019	6
2020	6
2021	6
2022	6
2023	6