Year Number 2000 32000 2001 33000 2002 34000 2003 34000 2004 33000 2005 30000 2006 28000 2007 26000 2008 25000 2009 24000 2010 21000 2011 20000 2012 19000 2013 18000 2014 17000 2015 16000 2016 15000 2017 14000 2018 13000 2019 13000 2020 12000