Year Number 2004-01-01 14400000 2005-01-01 18820000 2006-01-01 22890000 2007-01-01 20567490 2008-01-01 23579270 2009-01-01 24901152 2010-01-01 26388150 2011-01-01 26044130 2012-01-01 24637184 2013-01-01 24617934 2014-01-01 25112574 2015-01-01 25900199 2016-01-01 28819083