Year US Dollars adjusted for inflation) 1960 21000000 1961 12000000 1962 20000000 1963 74000000 1964 50000000 1965 77000000 1966 508000000 1967 889000000 1968 805000000 1969 856000000 1970 859000000 1971 735000000 1972 1502000000 1973 3276000000 1974 3420000000 1975 1411000000 1976 527000000 1977 931000000 1978 871000000 1979 2045000000 1980 1859000000 1981 1338000000 1982 1973000000 1983 2233000000 1984 1809000000 1985 1575000000 1986 1262000000 1987 1409000000 1988 1312000000 1989 663000000 1990 739000000 1991 320000000 1992 240000000 1993 171000000 1994 19000000 1995 35000000 1996 35000000 1997 35000000 1998 55000000 1999 58000000 2000 64000000 2001 28000000 2002 45000000 2003 69000000 2004 25000000 2005 35000000 2006 100000000 2007 20000000 2008 294000000 2009 205000000 2010 413000000 2011 493000000 2012 516000000 2013 506000000 2014 21000000 2015 22000000 2016 8000000 2017 37000000 2018 199000000 2019 36000000 2020 84000000 2021 11000000