Year	Number
2004-01-01	20.7714
2005-01-01	20.5841
2006-01-01	21.7014
2007-01-01	25.3620
2008-01-01	25.2067
2009-01-01	23.8012
2010-01-01	26.1399
2011-01-01	25.9994
2012-01-01	19.6952
2013-01-01	31.8144
2014-01-01	31.6352
2015-01-01	33.8958
2016-01-01	34.8541
2017-01-01	36.0560