Year Number 1995 4520000 1996 5061000 1997 5324000 1998 8426000 1999 9232000 2000 10473000 2001 12133000 2002 16602000 2003 20222000 2004 28853000 2005 31026000 2006 34524000 2007 40954000 2008 45844000 2009 47656000 2010 57386000 2011 70250000 2012 83182000 2013 98185000 2014 116593000 2015 127860000 2016 135130000 2017 143035000 2018 149720000 2019 154632000 2020 20334000