Bi-annual US dollars 1987-06-30 756 1987-12-31 749 1988-06-30 662 1988-12-31 607 1989-06-30 801 1989-12-31 701 1990-06-30 698 1990-12-31 758 1991-06-30 628 1991-12-31 575 1992-06-30 641 1992-12-31 542 1993-06-30 498 1993-12-31 350 1994-06-30 227 1994-12-31 283 1995-06-30 162 1995-12-31 287 1996-06-30 670 1996-12-31 353 1997-06-30 1160 1997-12-31 1142 1998-06-30 524 1998-12-31 664 1999-06-30 883