Year	number
2003	11
2004	10.584415584415584
2005	10.5
2006	10.417582417582418
2007	10.021978021978022
2008	9.582417582417582
2009	9.195652173913043
2010	9.021739130434783
2011	8.717391304347826
2012	8.627659574468085
2013	8.509803921568627
2014	8.392156862745098
2015	8.196078431372548
2016	8
2017	7.8431372549019605
2018	7.450980392156863
2019	7.245098039215686