Year US Dollars adjusted for inflation) 1960 31000000 1961 157000000 1962 28000000 1963 41000000 1964 45000000 1965 63000000 1966 241000000 1967 283000000 1968 373000000 1969 338000000 1970 370000000 1971 177000000 1972 16000000 1973 16000000 1974 117000000 1975 326000000 1976 64000000 1977 94000000 1978 128000000 1979 5000000 1980 36000000 1981 57000000 1982 184000000 1983 12000000 1984 109000000 1985 154000000 1986 5000000 1987 9000000 1988 90000000 1989 135000000 1990 70000000 1991 1012000000 1992 19000000 1993 350000000 1994 453000000 1995 20000000 1996 8000000 1997 0 1998 16000000 1999 3000000 2000 2000000 2001 19000000 2003 29000000 2004 70000000 2005 158000000 2006 220000000 2007 60000000 2008 144000000 2009 370000000 2010 892000000 2011 165000000 2012 42000000 2013 11000000 2014 3000000 2015 1000000 2016 21000000 2017 8000000 2018 19000000 2019 44000000 2020 45000000 2021 6000000