Year	2007 US$
1967	3441000000
1968	4007000000
1969	2910000000
1970	2817000000
1971	6411000000
1972	6622000000
1973	5911000000
1974	7414000000
1975	7861000000
1976	7228000000
1977	7214000000
1978	8010000000
1979	8550000000
1980	9009000000
1981	9421000000
1982	9900000000
1983	9993000000
1984	11010000000
1985	8709000000
1986	7894000000
1987	8091000000
1988	8562000000
1989	10070000000
1990	10170000000
1991	5850000000
1992	5860000000
1993	5765000000
1994	5808000000
1995	5621000000
1996	5646000000
1997	5637000000
1998	5012000000
1999	4773000000
2000	3606000000
2001	3619000000
2002	3623000000
2003	3965000000
2004	4348000000
2005	4272000000
2006	5258000000
2007	5244000000