Bi-annual US dollars 1987-06-30 35 1987-12-31 19 1988-06-30 26 1988-12-31 9 1989-06-30 8 1989-12-31 8 1990-06-30 9 1990-12-31 4 1991-06-30 6 1991-12-31 6 1992-06-30 10 1992-12-31 11 1993-06-30 11 1993-12-31 15 1994-06-30 15 1994-12-31 13 1995-06-30 25 1995-12-31 12 1996-06-30 2 1996-12-31 14 1997-06-30 3 1997-12-31 13 1998-06-30 7 1998-12-31 3 1999-06-30 3