Year	2007 US$
1960	14.5
1961	13.82
1962	10.36
1963	15.76
1964	12.42
1965	24.28
1966	27.09
1967	34.26
1968	29.46
1969	33.7
1970	32.49
1971	33.07
1972	32.66
1973	41.73
1974	40.85
1975	38.84
1976	34.23
1977	37.09
1978	42.83
1979	52.2
1980	63.43
1981	55.5
1982	58.11
1983	66.88
1984	73.98
1985	63.41
1986	65.03
1987	72.16
1988	78.6
1989	80.91
1990	83.63
1991	90.82
1992	85.43
1993	75.12
1994	81.5
1995	82.19
1996	62.12
1997	67.92
1998	83.3
1999	83.8
2000	89.47
2001	74.26
2002	73.14
2003	65.73
2004	62.22
2005	94.46
2006	85.47
2007	60.11