Year	Number
2004-01-01	2.5581
2005-01-01	4.3605
2006-01-01	5.4070
2007-01-01	5.8721
2008-01-01	7.3837
2009-01-01	7.6163
2010-01-01	8.9535
2011-01-01	9.4186
2012-01-01	11.1628
2013-01-01	11.9186
2014-01-01	14.7674
2015-01-01	14.9419
2016-01-01	15.2326