Year	Number
2004-01-01	14.5957
2005-01-01	14.5789
2006-01-01	14.5789
2007-01-01	14.4582
2008-01-01	14.9143
2009-01-01	15.1591
2010-01-01	15.6991
2011-01-01	16.2894
2012-01-01	17.2553
2013-01-01	18.3151
2014-01-01	19.5627
2015-01-01	20.3240
2016-01-01	20.9176