Year	Number
2004-01-01	17.3647
2005-01-01	19.7070
2006-01-01	24.7990
2007-01-01	28.5927
2008-01-01	28.3912
2009-01-01	34.4239
2010-01-01	35.4584
2011-01-01	36.7412
2012-01-01	41.6064
2013-01-01	42.5151
2014-01-01	46.9211
2015-01-01	47.0105
2016-01-01	49.5926