Year US Dollars adjusted for inflation) 1960 1000000 1961 1000000 1963 0 1965 0 1968 1000000 1969 24000000 1970 9000000 1971 27000000 1972 2000000 1974 7000000 1975 2000000 1976 2000000 1978 35000000 1979 25000000 1980 17000000 1981 3000000 1982 11000000 1983 25000000 1984 25000000 1985 3000000 1988 28000000 1989 44000000 1990 44000000 1991 18000000 1997 27000000 1998 0 1999 1000000 2000 0 2003 8000000 2004 7000000 2005 4000000 2006 1000000 2007 0 2009 4000000 2010 28000000 2011 5000000 2012 23000000 2013 33000000 2014 6000000 2015 2000000 2018 0 2019 3000000 2021 3000000