Year	2007 US$
1960	86.99
1961	92.77
1962	98.79
1963	104
1964	101.6
1965	110.1
1966	100.5
1967	83.18
1968	91.96
1969	76.32
1970	66.91
1971	62.11
1972	74.9
1973	47.14
1974	59.27
1975	60.75
1976	59.61
1977	59.58
1978	66.63
1979	50.33
1980	69.49
1981	50.96
1982	67.48
1983	63.37
1984	65.27
1985	67.77
1986	66.83
1987	61.45
1988	65.51
1989	47.34
1990	67.08
1991	63.38
1992	63.69
1993	53.24
1994	50.63
1995	36.47
1996	45.14
1997	32.26
1998	40.34
1999	41.02
2000	43.31
2001	46.92
2002	53.03
2003	63.14
2004	73.39
2005	99.9
2006	80.71
2007	72.23