Year	Number
2004-01-01	15.4128
2005-01-01	22.1701
2006-01-01	25.3716
2007-01-01	28.3673
2008-01-01	31.6488
2009-01-01	30.5168
2010-01-01	28.8132
2011-01-01	27.6241
2012-01-01	26.0119
2013-01-01	23.0848
2014-01-01	20.7638
2015-01-01	20.1235
2016-01-01	20.0091
2017-01-01	18.9344