Bi-annual US dollars 1987-06-30 23 1987-12-31 68 1988-06-30 67 1988-12-31 49 1989-06-30 36 1989-12-31 37 1990-06-30 10 1990-12-31 4 1991-06-30 3 1991-12-31 13 1992-06-30 32 1992-12-31 12 1993-06-30 14 1993-12-31 16 1994-06-30 14 1994-12-31 5 1995-06-30 14 1995-12-31 11 1996-06-30 8 1996-12-31 10 1997-06-30 7 1997-12-31 12 1998-06-30 8 1998-12-31 5 1999-06-30 11