Year	Number
2004-01-01	0.9333
2005-01-01	0.9854
2006-01-01	1.0063
2007-01-01	1.2304
2008-01-01	1.3243
2009-01-01	1.3608
2010-01-01	1.2148
2011-01-01	1.4390
2012-01-01	1.5693
2013-01-01	1.6215
2014-01-01	1.6528
2015-01-01	1.7623
2016-01-01	1.8196
2017-01-01	1.7935
