Year Number 2004 1650000 2005 1938000 2006 2227000 2007 2451000 2008 2581000 2009 2681000 2010 2948000 2011 3299000 2012 3642000 2013 4010000 2014 4062000 2015 4381000 2016 4718000 2017 4992000 2018 5384000 2019 5275000 2020 1119000