Bi-annual	US dollars
1987-06-30	551
1987-12-31	604
1988-06-30	520
1988-12-31	504
1989-06-30	516
1989-12-31	605
1990-06-30	525
1990-12-31	573
1991-06-30	615
1991-12-31	484
1992-06-30	447
1992-12-31	336
1993-06-30	657
1993-12-31	596
1994-06-30	741
1994-12-31	807
1995-06-30	748
1995-12-31	735
1996-06-30	721
1996-12-31	597
1997-06-30	795
1997-12-31	592
1998-06-30	775
1998-12-31	634
1999-06-30	624