Year	Number
2004-01-01	3.3942
2005-01-01	7.4818
2006-01-01	11.2774
2007-01-01	15.8029
2008-01-01	23.4307
2009-01-01	27.0438
2010-01-01	28.1387
2011-01-01	29.3796
2012-01-01	30.0365
2013-01-01	30.0000
2014-01-01	29.5985
2015-01-01	30.1460
2016-01-01	29.1971