Year US Dollars adjusted for inflation) 1975 0 1978 0 1980 0 1981 0 1983 1000000 1986 3000000 1987 3000000 1988 4000000 1989 4000000 1991 3000000 1992 8000000 1996 29000000 1998 2000000 1999 1000000 2000 1000000 2002 1000000 2008 100000000 2014 20000000 2018 0