Bi-annual US dollars 1987-06-30 2 1987-12-31 2 1988-06-30 12 1988-12-31 4 1989-06-30 11 1989-12-31 8 1990-06-30 7 1990-12-31 2 1991-06-30 5 1991-12-31 7 1992-06-30 11 1992-12-31 8 1993-06-30 12 1993-12-31 40 1994-06-30 39 1994-12-31 14 1995-06-30 22 1995-12-31 20 1996-06-30 59 1996-12-31 58 1997-06-30 25 1997-12-31 21 1998-06-30 23 1998-12-31 22 1999-06-30 35