Year	Number
2004-01-01	38.2776
2005-01-01	41.4861
2006-01-01	44.4310
2007-01-01	48.0195
2008-01-01	49.6544
2009-01-01	50.0799
2010-01-01	51.2416
2011-01-01	52.5772
2012-01-01	54.7019
2013-01-01	56.2209
2014-01-01	58.9254
2015-01-01	59.5232
2016-01-01	60.1325
2017-01-01	60.7632