Year	Number
2004-01-01	1.7380
2005-01-01	1.8506
2006-01-01	1.8798
2007-01-01	2.0008
2008-01-01	1.9983
2010-01-01	2.8131
2011-01-01	3.4468
2012-01-01	3.4247
2013-01-01	3.3664
2015-01-01	3.3289