Year	2007 US$
1967	20850000
1968	22950000
1969	29470000
1970	74440000
1971	124700000
1972	168200000
1973	342700000
1974	482000000
1975	451900000
1976	374100000
1977	546000000
1978	666000000
1979	610200000
1980	560700000
1981	587900000
1982	750000000
1983	710300000
1984	1038000000
1985	1009000000
1986	1293000000
1987	865500000
1988	450200000
1989	548500000
1990	734800000
1991	871700000
1992	693800000
1993	749900000
1994	854300000
1995	1130000000
1996	953500000
1997	753200000
1998	812800000
1999	1548000000
2000	952200000
2001	1532000000
2002	1568000000
2003	1399000000
2004	1429000000
2005	1647000000
2006	1677000000
2007	2014000000