Year	number
2003	10.552631578947368
2004	10.365853658536585
2005	10.5
2006	10.5
2007	10.26086956521739
2008	9.869565217391305
2009	9.630434782608695
2010	9.41304347826087
2011	9.065217391304348
2012	9
2013	8.959411764705882
2014	8.772549019607842
2015	8.537254901960784
2016	8.360784313725489
2017	8.155490196078432
2018	7.734509803921569
2019	7.313725490196078