Bi-annual US dollars 1987-06-30 58 1987-12-31 87 1988-06-30 78 1988-12-31 76 1989-06-30 56 1989-12-31 53 1990-06-30 56 1990-12-31 64 1991-06-30 70 1991-12-31 84 1992-06-30 76 1992-12-31 88 1993-06-30 77 1993-12-31 72 1994-06-30 94 1994-12-31 69 1995-06-30 41 1995-12-31 113 1996-06-30 57 1996-12-31 68 1997-06-30 85 1997-12-31 74 1998-06-30 127 1998-12-31 92 1999-06-30 99