Year	Number
2004-01-01	4.3070
2005-01-01	4.6170
2006-01-01	5.9094
2007-01-01	7.2598
2008-01-01	9.9458
2009-01-01	10.2950
2010-01-01	12.1277
2011-01-01	12.9049
2012-01-01	14.0009
2013-01-01	14.0107
2014-01-01	14.1062
2015-01-01	14.9656
2016-01-01	16.7933
2017-01-01	16.1148