Year	Number
2004-01-01	2.7187
2005-01-01	5.7406
2006-01-01	6.9468
2007-01-01	15.5223
2008-01-01	24.7363
2009-01-01	31.3832
2010-01-01	36.8723
2011-01-01	43.0516
2012-01-01	46.0186
2013-01-01	49.2308
2014-01-01	51.6593
2015-01-01	54.6231
2016-01-01	56.3486
2017-01-01	57.6934