Bi-annual US dollars 1987-06-30 722 1987-12-31 813 1988-06-30 733 1988-12-31 560 1989-06-30 612 1989-12-31 600 1990-06-30 567 1990-12-31 272 1991-06-30 212 1991-12-31 248 1992-06-30 181 1992-12-31 250 1993-06-30 588 1993-12-31 392 1994-06-30 316 1994-12-31 277 1995-06-30 383 1995-12-31 389 1996-06-30 424 1996-12-31 253 1997-06-30 371 1997-12-31 387 1998-06-30 445 1998-12-31 501 1999-06-30 459