Year	Number
2004-01-01	18750
2005-01-01	16171
2006-01-01	20881
2007-01-01	19690
2008-01-01	21123
2009-01-01	21479
2010-01-01	23994
2011-01-01	24233
2012-01-01	26905
2013-01-01	29249
2014-01-01	29372