Bi-annual US dollars 1987-06-30 1055 1987-12-31 1060 1988-06-30 1006 1988-12-31 1372 1989-06-30 1347 1989-12-31 818 1990-06-30 509 1990-12-31 511 1991-06-30 733 1991-12-31 743 1992-06-30 864 1992-12-31 653 1993-06-30 797 1993-12-31 837 1994-06-30 1049 1994-12-31 1126 1995-06-30 1304 1995-12-31 1123 1996-06-30 1179 1996-12-31 1103 1997-06-30 1033 1997-12-31 1048 1998-06-30 935 1998-12-31 1020 1999-06-30 1047