Year	Number
2004-01-01	0.2000
2005-01-01	0.1989
2006-01-01	0.2154
2007-01-01	0.2397
2008-01-01	0.2556
2009-01-01	0.2687
2010-01-01	0.2567
2011-01-01	0.2622
2012-01-01	0.2534
2013-01-01	0.2328
2014-01-01	0.2117
2015-01-01	0.2132
2016-01-01	0.2191