Bi-annual US dollars 1987-06-30 29 1987-12-31 17 1988-06-30 3 1988-12-31 2 1989-06-30 2 1989-12-31 0 1990-06-30 2 1990-12-31 39 1991-06-30 3 1991-12-31 4 1992-06-30 38 1992-12-31 42 1993-06-30 14 1993-12-31 24 1994-06-30 23 1994-12-31 22 1995-06-30 13 1995-12-31 8 1996-06-30 9 1996-12-31 12 1997-06-30 30 1997-12-31 3 1998-06-30 5 1998-12-31 5 1999-06-30 5