Year	Number
2001	7.58033
2002	6.72334
2003	6.81871
2004	6.89086
2005	6.98452
2006	5.83924
2010	5.21144
2011	6.45397
2012	6.1459
2013	4.94815
2014	4.57933
2015	6.02251