Bi-annual US dollars 1987-06-30 5 1987-12-31 13 1988-06-30 5 1988-12-31 7 1989-06-30 3 1989-12-31 0 1990-06-30 0 1990-12-31 0 1991-06-30 0 1991-12-31 0 1992-06-30 0 1992-12-31 0 1993-06-30 8 1993-12-31 15 1994-06-30 31 1994-12-31 55 1995-06-30 64 1995-12-31 53 1996-06-30 81 1996-12-31 82 1997-06-30 171 1997-12-31 240 1998-06-30 150 1998-12-31 153 1999-06-30 -214