Year	number
2003	10.465116279069768
2004	10.229166666666666
2005	10.358490566037736
2006	10.222222222222221
2007	10
2008	9.407407407407407
2009	8.927272727272728
2010	8.763636363636364
2011	8.290909090909091
2012	8.24561403508772
2013	8.068965517241379
2014	7.793103448275862
2015	7.677966101694915
2016	7.423728813559322
2017	7.203389830508475
2018	7.084745762711864
2019	6.898305084745763