Bi-annual US dollars 1987-06-30 32 1987-12-31 21 1988-06-30 9 1988-12-31 5 1989-06-30 0 1989-12-31 0 1990-06-30 0 1990-12-31 0 1991-06-30 0 1991-12-31 2 1992-06-30 2 1992-12-31 2 1993-06-30 3 1993-12-31 1 1994-06-30 3 1994-12-31 8 1995-06-30 32 1995-12-31 37 1996-06-30 67 1996-12-31 21 1997-06-30 28 1997-12-31 36 1998-06-30 25 1998-12-31 32 1999-06-30 27