Year	Number
2004-01-01	4.4776
2005-01-01	5.1012
2006-01-01	5.7295
2007-01-01	5.9150
2008-01-01	6.2838
2009-01-01	6.9012
2010-01-01	8.5983
2011-01-01	9.2984
2012-01-01	9.7105
2013-01-01	11.4843
2014-01-01	15.0538
2015-01-01	15.3208