Year	Number
2004-01-01	15.1391
2005-01-01	17.0779
2006-01-01	19.3302
2007-01-01	22.6792
2008-01-01	24.6964
2009-01-01	27.5950
2010-01-01	29.3576
2011-01-01	35.7814
2012-01-01	37.7791
2013-01-01	51.0967
2014-01-01	57.3443
2015-01-01	44.7904
2016-01-01	47.4344
2017-01-01	48.8445