Year	Number
2004	6.02431
2005	5.89781
2006	5.4
2007	5.32813
2008	6.41091
2009	6.21754
2010	5.58675
2011	6.8549
2012	5.35802
2014	6.03463
2015	6.15354
2016	5.63139
2017	5.59854