Year	Number
2002	3.70833
2003	4.02632
2004	3.94048
2006	4.95062
2008	5.27586
2012	3.12739
2013	5.02804
2014	4.88235
2015	4.55455
2016	3.85915
2017	3.90728
2018	4.42958