Year	Number
2007-01-01	3.9387
2008-01-01	4.1182
2009-01-01	4.1353
2010-01-01	4.1454
2011-01-01	4.1045
2012-01-01	4.5897
2013-01-01	6.5334
2014-01-01	6.7774
2015-01-01	7.1217
2016-01-01	8.3071