Year	Number
2008-01-01	0.3070
2009-01-01	0.3539
2010-01-01	0.3523
2011-01-01	0.3578
2012-01-01	0.3852
2013-01-01	0.4156
2014-01-01	0.4109
2015-01-01	0.4992
2016-01-01	0.5180
2017-01-01	0.5328