Year Number of 2000 33000 2001 32000 2002 34000 2003 32000 2004 32000 2005 31000 2006 30000 2007 28000 2008 28000 2009 29000 2010 28000 2011 27000 2012 27000 2013 27000 2014 27000 2015 27000 2016 28000 2017 28000 2018 29000 2019 29000 2020 32000