Year current US$ 2001 9760000000 2002 11362000000 2003 13427000000 2004 16082000000 2005 17963000000 2006 18850000000 2007 22456000000 2008 26401000000 2009 23785000000 2010 30169000000 2011 37343000000 2012 48096000000 2013 59504000000 2014 55383000000 2015 38432000000 2016 27654000000 2017 35584000000 2018 38791000000 2019 40611000000 2020 10800000000