Year	Number
2007-01-01	14981702
2008-01-01	16178570
2009-01-01	17162911
2010-01-01	18228015
2011-01-01	19499288
2012-01-01	21016009
2013-01-01	22402550
2014-01-01	24535185
2015-01-01	24363384
2016-01-01	24619643