Year	Number
2004-01-01	28.4831
2005-01-01	30.6004
2006-01-01	33.4518
2007-01-01	37.4389
2008-01-01	43.0145
2009-01-01	46.1347
2010-01-01	52.2115
2011-01-01	58.7916
2012-01-01	63.2248
2013-01-01	71.6463
2014-01-01	76.4689
2015-01-01	79.3518
2016-01-01	78.0767
2017-01-01	79.7014