Year	Number
2004-01-01	2.7356
2005-01-01	2.6277
2006-01-01	2.7213
2007-01-01	3.5513
2008-01-01	4.1217
2009-01-01	4.4160
2010-01-01	4.7124
2011-01-01	4.9795
2012-01-01	5.2524
2013-01-01	5.3464
2014-01-01	5.5447
2015-01-01	5.6521
2016-01-01	5.4315