Year current US$ 2000 4000000 2001 5000000 2002 12000000 2003 14000000 2004 12000000 2005 1000000 2006 2000000 2007 5000000 2008 20000000 2009 33000000 2010 33000000 2011 41000000 2012 44000000 2013 47000000 2014 48000000 2015 43000000 2016 50000000 2017 55000000 2018 58000000 2019 57000000