Year current US$ 1980 37000000 1981 29000000 1982 17000000 1983 23000000 1984 41000000 1985 23000000 1986 65000000 1987 29000000 1988 31000000 1989 50000000 1990 60000000 1991 55000000 1992 85000000 1993 35000000 1994 32000000 1995 56000000 1996 68000000 1997 57000000 1998 45000000 1999 51000000 2000 51000000 2001 36000000 2002 56000000 2003 52000000 2004 73000000 2005 49000000 2006 27000000 2007 27000000 2008 24000000 2009 29000000 2010 15000000 2011 13000000 2012 11000000 2013 12000000 2014 22000000 2015 22000000 2016 19000000 2017 18000000 2018 18000000 2019 27000000 2020 19000000 2021 29000000 2022 34000000 2023 27000000