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