Year	Number
2004-01-01	4.8998
2005-01-01	5.0223
2006-01-01	5.0408
2007-01-01	5.0696
2008-01-01	5.3180
2009-01-01	5.2360
2010-01-01	5.4372
2011-01-01	5.7430
2012-01-01	6.1986
2013-01-01	6.4768