Year	number
2003	11.958333333333334
2004	11.655172413793103
2005	11.848484848484848
2006	11.588235294117647
2007	11.294117647058824
2008	10.764705882352942
2009	10.264705882352942
2010	9.911764705882353
2011	9.264705882352942
2012	8.971428571428572
2013	8.722222222222221
2014	8.36111111111111
2015	8.324324324324325
2016	7.891891891891892
2017	7.513513513513513
2018	7.351351351351352
2019	7.27027027027027