Year 2007 US$ 1960 20.4 1961 25.8 1962 26.27 1963 34.23 1964 31.57 1965 35.26 1966 41.66 1967 41.31 1968 71.87 1969 76.11 1970 83.41 1971 88.5 1972 116.6 1973 127.1 1974 165.2 1975 199.8 1976 228.7 1977 278.8 1978 309.2 1979 341.2 1980 331.1 1981 326.7 1982 396.3 1983 436.1 1984 424.4 1985 450.7 1986 539.5 1987 509.3 1988 517.2 1989 480.9 1990 550.1 1991 542.6 1992 562.2 1993 497.6 1994 552.1 1995 524.4 1996 537.9 1997 567 1998 614 1999 612.7 2000 547.7 2001 583.6 2002 659 2003 680.1 2004 656.3 2005 726.9 2006 702.3 2007 786.5