Year	2007 US$
1960	20.13
1961	15.19
1962	19.13
1963	15.38
1964	9.729
1965	11.68
1966	14.81
1967	28.17
1968	25.93
1969	22.11
1970	23.32
1971	26.51
1972	13.06
1973	21.58
1974	22.4
1975	16.16
1976	21.58
1977	16.81
1978	26.99
1979	16.48
1980	34.99
1981	38.05
1982	46.74
1983	46.7
1984	66.13
1985	63.63
1986	101.1
1987	90.1
1988	103.3
1989	115.9
1990	87.9
1991	83.4
1992	97.52
1993	89.06
1994	78.17
1995	45.03
1996	60.5
1997	34.04
1998	60.78
1999	49.5
2000	42.72
2001	50.33
2002	65.74
2003	55.9
2004	50.05
2005	99.67
2006	69.12
2007	67.44