Bi-annual US dollars 1987-06-30 48 1987-12-31 38 1988-06-30 27 1988-12-31 22 1989-06-30 17 1989-12-31 18 1990-06-30 12 1990-12-31 6 1991-06-30 6 1991-12-31 4 1992-06-30 4 1992-12-31 0 1993-06-30 18 1993-12-31 18 1994-06-30 19 1994-12-31 19 1995-06-30 16 1995-12-31 16 1996-06-30 14 1996-12-31 12 1997-06-30 12 1997-12-31 12 1998-06-30 12 1998-12-31 12 1999-06-30 9