Year Number 2001 5499000 2002 4989000 2003 4301000 2004 4612000 2005 4850000 2006 4171000 2007 5915000 2009 8365000 2010 8363000 2011 9521000 2012 8577000 2013 9438000 2014 11200000 2015 9308000