Bi-annual US dollars 1987-06-30 0 1987-12-31 0 1988-06-30 9 1988-12-31 13 1989-06-30 6 1989-12-31 5 1990-06-30 31 1990-12-31 31 1991-06-30 8 1991-12-31 9 1992-06-30 10 1992-12-31 0 1993-06-30 11 1993-12-31 10 1994-06-30 6 1994-12-31 53 1995-06-30 14 1995-12-31 20 1996-06-30 37 1996-12-31 19 1997-06-30 22 1997-12-31 18 1998-06-30 20 1998-12-31 43 1999-06-30 11