Year US Dollars adjusted for inflation) 1960 14000000 1961 17000000 1962 2000000 1963 3000000 1964 15000000 1965 9000000 1966 26000000 1967 12000000 1968 57000000 1969 155000000 1970 371000000 1971 540000000 1972 534000000 1973 733000000 1974 1767000000 1975 1637000000 1976 1875000000 1977 3056000000 1978 4214000000 1979 3166000000 1980 2941000000 1981 3172000000 1982 2768000000 1983 1410000000 1984 731000000 1985 750000000 1986 401000000 1987 184000000 1988 9000000 1989 218000000 1990 11000000 1999 9000000 2005 1000000 2006 16000000 2007 16000000 2008 16000000 2009 22000000 2010 37000000 2011 8000000 2012 73000000 2013 116000000