Year	number
2003	11.375
2004	11.166666666666666
2005	11.372093023255815
2006	11.159090909090908
2007	10.863636363636363
2008	10.25
2009	9.727272727272727
2010	9.522727272727273
2011	8.977272727272727
2012	8.822222222222223
2013	8.662173913043478
2014	8.444782608695652
2015	8.43531914893617
2016	8.052340425531916
2017	7.690638297872341
2018	7.499148936170213
2019	7.404255319148936