Bi-annual US dollars 1987-06-30 24 1987-12-31 11 1988-06-30 27 1988-12-31 13 1989-06-30 25 1989-12-31 6 1990-06-30 31 1990-12-31 4 1991-06-30 16 1991-12-31 26 1992-06-30 29 1992-12-31 50 1993-06-30 44 1993-12-31 19 1994-06-30 25 1994-12-31 14 1995-06-30 76 1995-12-31 45 1996-06-30 20 1996-12-31 94 1997-06-30 12 1997-12-31 117 1998-06-30 72 1998-12-31 68 1999-06-30 112