Year	Number
2004-01-01	2.3572
2005-01-01	2.3435
2006-01-01	2.3121
2007-01-01	2.2593
2008-01-01	2.5497
2009-01-01	2.5041
2010-01-01	2.6226
2011-01-01	6.3852
2012-01-01	6.5261
2013-01-01	7.0619
2014-01-01	3.9427
2015-01-01	3.2447
2016-01-01	3.3091