Bi-annual US dollars 1987-06-30 927 1987-12-31 1240 1988-06-30 1100 1988-12-31 1074 1989-06-30 794 1989-12-31 716 1990-06-30 809 1990-12-31 828 1991-06-30 632 1991-12-31 697 1992-06-30 976 1992-12-31 701 1993-06-30 902 1993-12-31 798 1994-06-30 739 1994-12-31 703 1995-06-30 843 1995-12-31 863 1996-06-30 736 1996-12-31 1023 1997-06-30 1206 1997-12-31 1708 1998-06-30 1466 1998-12-31 1538 1999-06-30 1462