Bi-annual US dollars 1987-06-30 887 1987-12-31 900 1988-06-30 783 1988-12-31 828 1989-06-30 767 1989-12-31 508 1990-06-30 474 1990-12-31 608 1991-06-30 504 1991-12-31 549 1992-06-30 537 1992-12-31 426 1993-06-30 464 1993-12-31 402 1994-06-30 404 1994-12-31 388 1995-06-30 507 1995-12-31 437 1996-06-30 522 1996-12-31 625 1997-06-30 476 1997-12-31 1099 1998-06-30 1012 1998-12-31 972 1999-06-30 804