Year	Number
2004-01-01	4.4558
2005-01-01	4.6186
2006-01-01	5.1005
2007-01-01	5.4152
2008-01-01	6.0677
2009-01-01	7.1529
2010-01-01	7.7055
2011-01-01	14.2230
2012-01-01	16.5961
2013-01-01	17.6460
2014-01-01	18.1379
2015-01-01	18.2532
2016-01-01	18.1312