Year	2007 US$
1967	311600000
1968	76660000
1969	708300000
1970	694500000
1971	864800000
1972	921700000
1973	1527000000
1974	1129000000
1975	1212000000
1976	1277000000
1977	1668000000
1978	1981000000
1979	1464000000
1980	1013000000
1981	1618000000
1982	1432000000
1983	1983000000
1984	2255000000
1985	1756000000
1986	1264000000
1987	1874000000
1988	1819000000
1989	1422000000
1990	1233000000
1991	1279000000
1992	1634000000
1993	1046000000
1994	1008000000
1995	1354000000
1996	1308000000
1997	955200000
1998	1018000000
1999	852500000
2000	1240000000
2001	996100000
2002	1383000000
2003	1804000000
2004	1891000000
2005	1866000000
2006	1686000000
2007	2374000000