Year US Dollars adjusted for inflation) 1960 2000000 1961 1000000 1962 1000000 1963 6000000 1964 1000000 1965 1000000 1970 21000000 1971 13000000 1973 1000000 1974 5000000 1975 5000000 1976 15000000 1977 29000000 1978 17000000 1979 24000000 1981 19000000 1982 16000000 1984 0 1985 3000000 1989 8000000 1990 16000000 1991 18000000 1994 16000000 1995 2000000 1996 2000000 1997 8000000 1998 4000000 2000 31000000 2002 27000000 2003 7000000 2010 10000000 2011 5000000 2012 11000000 2014 8000000 2015 1000000 2016 35000000 2018 1000000 2019 34000000