Year	2007 US$
1967	2866000000
1968	1748000000
1969	1741000000
1970	1818000000
1971	2615000000
1972	2880000000
1973	2966000000
1974	4998000000
1975	3596000000
1976	3850000000
1977	4630000000
1978	4838000000
1979	6465000000
1980	6350000000
1981	7103000000
1982	6123000000
1983	5098000000
1984	6836000000
1985	5653000000
1986	5371000000
1987	6292000000
1988	6734000000
1989	6304000000
1990	5405000000
1991	4892000000
1992	4754000000
1993	4972000000
1994	5479000000
1995	5606000000
1996	6310000000
1997	5136000000
1998	4522000000
1999	4583000000
2000	3728000000
2001	4417000000
2002	4223000000
2003	4688000000
2004	5311000000
2005	5150000000
2006	6308000000
2007	5977000000