Year	Number
2004-01-01	18787282
2005-01-01	20381957
2006-01-01	21545096
2007-01-01	21647824
2008-01-01	23534081
2009-01-01	24975308
2010-01-01	29668667
2011-01-01	34032104
2012-01-01	31501567
2013-01-01	34314443
2014-01-01	35663563
2015-01-01	38343412
2016-01-01	40566054