Year Number 2000 38000 2001 35000 2002 34000 2003 31000 2004 33000 2005 32000 2006 30000 2007 30000 2008 29000 2009 28000 2010 26000 2011 27000 2012 25000 2013 23000 2014 22000 2015 21000 2016 21000 2017 20000 2018 19000 2019 17000 2020 17000