Bi-annual US dollars 1987-06-30 0 1987-12-31 0 1988-06-30 0 1988-12-31 0 1989-06-30 9 1989-12-31 8 1990-06-30 5 1990-12-31 8 1991-06-30 3 1991-12-31 17 1992-06-30 27 1992-12-31 12 1993-06-30 5 1993-12-31 7 1994-06-30 17 1994-12-31 25 1995-06-30 25 1995-12-31 3 1996-06-30 19 1996-12-31 22 1997-06-30 2 1997-12-31 79 1998-06-30 2 1998-12-31 18 1999-06-30 3