Year	Number
2004-01-01	31.5877
2005-01-01	31.8824
2006-01-01	33.4119
2007-01-01	37.3592
2008-01-01	36.6082
2009-01-01	35.3482
2010-01-01	34.1838
2011-01-01	32.7650
2012-01-01	24.6380
2013-01-01	21.6007
2014-01-01	20.3954
2015-01-01	18.0539
2016-01-01	17.0916