Bi-annual US dollars 1987-06-30 8 1987-12-31 13 1988-06-30 10 1988-12-31 7 1989-06-30 3 1989-12-31 0 1990-06-30 2 1990-12-31 0 1991-06-30 6 1991-12-31 6 1992-06-30 6 1992-12-31 129 1993-06-30 173 1993-12-31 7 1994-06-30 8 1994-12-31 9 1995-06-30 6 1995-12-31 6 1996-06-30 2 1996-12-31 7 1997-06-30 10 1997-12-31 10 1998-06-30 8 1998-12-31 3 1999-06-30 2