Year US Dollars adjusted for inflation) 1960 10000000 1961 2000000 1962 0 1963 11000000 1965 30000000 1966 52000000 1967 72000000 1968 4000000 1969 1000000 1972 21000000 1973 165000000 1974 283000000 1975 128000000 1976 180000000 1977 44000000 1978 57000000 1979 48000000 1980 122000000 1981 97000000 1982 61000000 1983 23000000 1984 15000000 1985 42000000 1986 15000000 1990 16000000 1999 1000000 2013 3000000 2015 1000000 2016 2000000 2017 2000000 2019 8000000 2020 2000000 2021 2000000