Bi-annual US dollars 1987-06-30 324 1987-12-31 177 1988-06-30 101 1988-12-31 172 1989-06-30 177 1989-12-31 776 1990-06-30 863 1990-12-31 866 1991-06-30 923 1991-12-31 693 1992-06-30 799 1992-12-31 598 1993-06-30 495 1993-12-31 542 1994-06-30 545 1994-12-31 701 1995-06-30 640 1995-12-31 575 1996-06-30 536 1996-12-31 277 1997-06-30 135 1997-12-31 574 1998-06-30 457 1998-12-31 508 1999-06-30 237