Year	Number
2004-01-01	18.3419
2005-01-01	20.8338
2006-01-01	23.0305
2007-01-01	23.9964
2008-01-01	25.9617
2009-01-01	28.3664
2010-01-01	31.4250
2011-01-01	35.7481
2012-01-01	41.0001
2013-01-01	48.7306
2014-01-01	52.6378
2015-01-01	58.0776
2016-01-01	64.0038
