Year	Number
2004-01-01	2.9874
2005-01-01	2.8635
2006-01-01	2.9116
2007-01-01	3.1891
2008-01-01	3.5463
2009-01-01	3.7221
2010-01-01	3.8526
2011-01-01	3.9992
2012-01-01	4.2170
2013-01-01	4.4490
2014-01-01	4.6927
2015-01-01	4.6620
2016-01-01	4.6762