Year	US Dollars
1974	385.66172
1975	503.79786
1976	563.88722
1977	501.08933
1978	390.99859
1979	316.42116
1980	446.17006
1981	888.52585
1982	1235.18847
1983	769.58207
1984	749.50904
1985	579.51344
1986	890.24638
1987	918.26925
1988	729.47484
1989	782.04326
1990	990.69095
1991	1419.41763
1992	1137.23684
1993	795.38818
1994	1096.3755
1995	367.52534
1996	264.45652
1997	254.31425
1998	349.20819
1999	410.36478
2000	354.7802
2001	340.68853
2002	199.04845
2003	101.20061
2004	137.74105
2005	216.71181
2006	-16.71442
2007	585.88398