Year	number
2003	11.558823529411764
2004	10.88888888888889
2005	10.545454545454545
2006	10.377777777777778
2007	9.822222222222223
2008	9.333333333333334
2009	8.804347826086957
2010	8.673913043478262
2011	8.41304347826087
2012	8.297872340425531
2013	8.117647058823529
2014	8.058823529411764
2015	7.901960784313726
2016	7.686274509803922
2017	7.588235294117647
2018	7.215686274509804
2019	7.215686274509804