Year Number 2000 26000 2001 28000 2002 29000 2003 30000 2004 30000 2005 29000 2006 27000 2007 26000 2008 25000 2009 24000 2010 23000 2011 22000 2012 20000 2013 18000 2014 16000 2015 14000 2016 13000 2017 12000 2018 12000 2019 13000 2020 13000