Bi-annual US dollars 1987-06-30 27 1987-12-31 34 1988-06-30 29 1988-12-31 33 1989-06-30 22 1989-12-31 23 1990-06-30 23 1990-12-31 29 1991-06-30 23 1991-12-31 24 1992-06-30 25 1992-12-31 18 1993-06-30 20 1993-12-31 19 1994-06-30 19 1994-12-31 17 1995-06-30 17 1995-12-31 16 1996-06-30 14 1996-12-31 7 1997-06-30 5 1997-12-31 0 1998-06-30 5 1998-12-31 10 1999-06-30 0