Year	Number
2004-01-01	35.6905
2005-01-01	34.3812
2006-01-01	33.7048
2007-01-01	32.9234
2008-01-01	33.4691
2009-01-01	34.1172
2010-01-01	27.9596
2011-01-01	26.9935
2012-01-01	24.4724
2013-01-01	22.8949
2014-01-01	21.9632
2015-01-01	21.9380
2016-01-01	21.5137
2017-01-01	20.9250