Year	Number
2004-01-01	2.7146
2005-01-01	3.8647
2006-01-01	5.4756
2007-01-01	7.2929
2008-01-01	8.7457
2009-01-01	8.1870
2010-01-01	7.7600
2011-01-01	6.7299
2012-01-01	7.1892
2013-01-01	1.5599
2014-01-01	1.6861
2015-01-01	1.6424
2016-01-01	1.4331
2017-01-01	1.2221