Year	Number
2004-01-01	4.2640
2005-01-01	4.3742
2006-01-01	4.5307
2007-01-01	5.1790
2008-01-01	6.6515
2009-01-01	6.7222
2010-01-01	6.7859
2011-01-01	7.0057
2012-01-01	7.5862
2013-01-01	7.7177
2014-01-01	8.0059
2015-01-01	8.1286
2016-01-01	7.9612
2017-01-01	7.6697