Bi-annual US dollars 1987-06-30 16 1987-12-31 11 1988-06-30 5 1988-12-31 7 1989-06-30 8 1989-12-31 6 1990-06-30 5 1990-12-31 2 1991-06-30 3 1991-12-31 15 1992-06-30 4 1992-12-31 11 1993-06-30 9 1993-12-31 22 1994-06-30 23 1994-12-31 0 1995-06-30 0 1995-12-31 11 1996-06-30 0 1996-12-31 22 1997-06-30 7 1997-12-31 2 1998-06-30 13 1998-12-31 7 1999-06-30 5