Year current US$ 1995 16358000000 1996 17748000000 1997 17490000000 1998 18819000000 1999 25204000000 2000 22537000000 2001 22611000000 2002 23779000000 2003 28075000000 2004 29469000000 2005 31347000000 2006 32347000000 2007 37898000000 2008 40928000000 2009 36991000000 2010 38297000000 2011 44725000000 2012 39836000000 2013 42183000000 2014 48777000000 2015 39521000000 2016 40436000000 2017 44192000000 2018 49464000000 2019 50507000000 2020 27758000000