Year	Number
2004-01-01	15.8326
2005-01-01	16.8217
2006-01-01	17.5894
2007-01-01	18.5362
2008-01-01	19.4646
2009-01-01	20.0438
2010-01-01	20.7000
2011-01-01	21.3173
2012-01-01	22.0985
2013-01-01	22.0862
2014-01-01	20.4644
2015-01-01	20.8857
2016-01-01	21.0098