Bi-annual US dollars 1987-06-30 40 1987-12-31 38 1988-06-30 27 1988-12-31 31 1989-06-30 20 1989-12-31 15 1990-06-30 16 1990-12-31 14 1991-06-30 16 1991-12-31 9 1992-06-30 6 1992-12-31 21 1993-06-30 26 1993-12-31 16 1994-06-30 11 1994-12-31 13 1995-06-30 5 1995-12-31 5 1996-06-30 3 1996-12-31 19 1997-06-30 13 1997-12-31 16 1998-06-30 12 1998-12-31 33 1999-06-30 27