Year	Number
2004-01-01	3278
2008-01-01	7754
2009-01-01	16016
2010-01-01	10463
2011-01-01	17291
2012-01-01	20915
2013-01-01	20007
2014-01-01	24197
2015-01-01	27713
2016-01-01	32544
2017-01-01	28126