Bi-annual US dollars 1987-06-30 564 1987-12-31 872 1988-06-30 919 1988-12-31 770 1989-06-30 530 1989-12-31 476 1990-06-30 497 1990-12-31 320 1991-06-30 229 1991-12-31 263 1992-06-30 284 1992-12-31 386 1993-06-30 362 1993-12-31 303 1994-06-30 164 1994-12-31 78 1995-06-30 80 1995-12-31 68 1996-06-30 44 1996-12-31 51 1997-06-30 62 1997-12-31 82 1998-06-30 132 1998-12-31 130 1999-06-30 128