Year	Number
2004-01-01	23.5547
2005-01-01	23.2376
2006-01-01	23.0612
2007-01-01	23.4241
2008-01-01	23.8009
2009-01-01	23.5191
2010-01-01	23.8447
2011-01-01	23.8333
2012-01-01	23.2582
2013-01-01	22.7948
2014-01-01	22.5285
2015-01-01	22.1297
2016-01-01	21.4319