Year Number 1997 115000 1998 148000 1999 147000 2000 171000 2001 139000 2002 160000 2003 165000 2004 190000 2005 217000 2006 256000 2007 306000 2008 322000 2009 311000 2010 365000 2011 392000 2012 439000 2013 529000 2014 536000 2015 678000 2016 778000 2017 923000 2018 1053000 2019 1198000 2020 197000