Year US Dollars adjusted for inflation) 1960 0 1961 8000000 1963 0 1964 4000000 1965 0 1966 1000000 1968 1000000 1969 38000000 1971 12000000 1973 1000000 1974 17000000 1976 15000000 1977 41000000 1978 20000000 1979 29000000 1982 7000000 1983 38000000 1984 4000000 1986 14000000 1987 18000000 1994 1000000 1995 6000000 2005 15000000 2006 15000000 2007 12000000 2008 6000000 2009 6000000 2010 4000000 2011 16000000 2014 7000000 2015 22000000 2016 40000000 2017 47000000 2018 15000000 2019 40000000 2020 22000000 2021 21000000 2022 18000000