Bi-annual US dollars 1987-06-30 818 1987-12-31 889 1988-06-30 1095 1988-12-31 725 1989-06-30 733 1989-12-31 979 1990-06-30 617 1990-12-31 365 1991-06-30 279 1991-12-31 403 1992-06-30 363 1992-12-31 750 1993-06-30 417 1993-12-31 328 1994-06-30 319 1994-12-31 466 1995-06-30 500 1995-12-31 400 1996-06-30 334 1996-12-31 416 1997-06-30 910 1997-12-31 484 1998-06-30 297 1998-12-31 644 1999-06-30 194