Year	Number
2004-01-01	45.6883
2005-01-01	54.5981
2006-01-01	66.9416
2007-01-01	81.4148
2008-01-01	96.5139
2009-01-01	106.1155
2010-01-01	112.1161
2011-01-01	123.4598
2012-01-01	135.4619
2013-01-01	138.5472
2014-01-01	142.7714
2015-01-01	145.7672
2016-01-01	160.5974
2017-01-01	177.7439