Year	Number
2004-01-01	16.7981
2005-01-01	17.3325
2006-01-01	17.8245
2007-01-01	18.3086
2008-01-01	18.6992
2009-01-01	18.1945
2010-01-01	18.1792
2011-01-01	18.2232
2012-01-01	18.3143
2013-01-01	18.0238
2014-01-01	17.2064
2015-01-01	16.7754
2016-01-01	16.2575