Year current US$ 1995 5000000 1996 4000000 1997 7000000 1998 8000000 1999 14000000 2000 15000000 2001 24000000 2002 36000000 2003 48000000 2004 76000000 2005 73000000 2006 167000000 2007 346000000 2008 514000000 2009 253000000 2010 160000000 2011 356000000 2012 434000000 2013 530000000 2014 423000000 2015 426000000 2016 432000000 2017 429000000 2018 459000000 2019 644000000 2020 151000000