Bi-annual US dollars 1987-06-30 108 1987-12-31 109 1988-06-30 77 1988-12-31 105 1989-06-30 64 1989-12-31 39 1990-06-30 30 1990-12-31 31 1991-06-30 24 1991-12-31 52 1992-06-30 67 1992-12-31 68 1993-06-30 81 1993-12-31 58 1994-06-30 91 1994-12-31 84 1995-06-30 35 1995-12-31 73 1996-06-30 84 1996-12-31 82 1997-06-30 12 1997-12-31 25 1998-06-30 60 1998-12-31 48 1999-06-30 52