Year	2007 US$
1974	12.02
1975	13.06
1976	14.5
1977	13.17
1978	31.99
1979	29.96
1980	26.43
1981	26.39
1982	42.58
1983	30.7
1984	34.75
1985	38.29
1986	45.12
1987	32.72
1988	34.11
1989	30.06
1990	30.69
1991	38.96
1992	34.53
1993	43.87
1994	56.43
1995	71.51
1996	80.87
1997	85.51
1998	89.36
1999	110.5
2000	113.6
2001	133.9
2002	167.2
2003	167
2004	179.5
2005	207.6
2006	266.4
2007	274.7