Bi-annual US dollars 1987-06-30 32 1987-12-31 47 1988-06-30 68 1988-12-31 83 1989-06-30 57 1989-12-31 18 1990-06-30 26 1990-12-31 71 1991-06-30 18 1991-12-31 32 1992-06-30 25 1992-12-31 18 1993-06-30 68 1993-12-31 16 1994-06-30 22 1994-12-31 23 1995-06-30 29 1995-12-31 6 1996-06-30 0 1996-12-31 43 1997-06-30 57 1997-12-31 16 1998-06-30 55 1998-12-31 5 1999-06-30 3