Year	number
2004	6.25
2005	6.111111111111111
2006	6.111111111111111
2007	6.05
2008	6.05
2009	5.85
2010	5.85
2011	5.85
2012	5.85
2013	5.85
2014	5.8
2015	5.523809523809524
2016	5.523809523809524
2017	5.476190476190476
2018	5.476190476190476
2019	5.142857142857143