Year	2007 US$
1967	863500000
1968	1889000000
1969	1031000000
1970	1761000000
1971	2347000000
1972	3762000000
1973	3492000000
1974	3225000000
1975	2563000000
1976	3424000000
1977	2586000000
1978	4338000000
1979	4988000000
1980	2851000000
1981	1854000000
1982	2509000000
1983	2306000000
1984	2381000000
1985	1362000000
1986	2080000000
1987	2109000000
1988	1927000000
1989	2321000000
1990	2349000000
1991	2804000000
1992	2077000000
1993	1857000000
1994	1632000000
1995	1824000000
1996	1758000000
1997	1490000000
1998	1973000000
1999	1975000000
2000	2343000000
2001	1952000000
2002	2815000000
2003	3150000000
2004	3434000000
2005	3469000000
2006	3581000000
2007	4974000000