Year current US$ 1996 68000000 1997 82000000 1998 97000000 1999 136000000 2000 108000000 2001 114000000 2002 113000000 2003 140000000 2004 134000000 2005 176000000 2006 179000000 2007 180000000 2008 208000000 2009 212000000 2010 216000000 2011 230000000 2012 186000000 2013 241000000 2014 253000000 2015 223000000 2016 245000000 2017 191000000 2018 132000000 2019 95000000 2020 90000000