Year	Number
2005-01-01	18.3239
2006-01-01	18.1969
2007-01-01	18.2513
2008-01-01	18.8817
2009-01-01	18.7790
2010-01-01	18.2610
2011-01-01	18.8086
2012-01-01	20.0747
2013-01-01	20.2685
2014-01-01	21.0856
2015-01-01	20.7225
2016-01-01	20.4006
2017-01-01	19.4686