Year	Number
2009-01-01	2.3487
2010-01-01	2.5379
2011-01-01	2.5542
2012-01-01	2.7156
2013-01-01	2.7544
2014-01-01	2.9081
2015-01-01	2.9429
2016-01-01	3.0377
2017-01-01	3.1929