Year	Number
2004-01-01	3.8217
2005-01-01	3.7209
2006-01-01	3.6227
2007-01-01	4.0223
2008-01-01	4.6396
2009-01-01	4.9865
2010-01-01	5.4915
2011-01-01	6.8576
2012-01-01	6.8048
2013-01-01	7.3788
2014-01-01	7.5907
2015-01-01	7.5101