Year	Number
2005-01-01	21030524
2006-01-01	20838506
2007-01-01	21032141
2008-01-01	21191661
2009-01-01	21332785
2010-01-01	21430058
2011-01-01	20515815
2012-01-01	19513925
2013-01-01	20535354
2014-01-01	20518991
2015-01-01	19590899
2016-01-01	19664311