Bi-annual US dollars 1987-06-30 92 1987-12-31 92 1988-06-30 49 1988-12-31 34 1989-06-30 68 1989-12-31 82 1990-06-30 99 1990-12-31 6 1991-06-30 11 1991-12-31 9 1992-06-30 11 1992-12-31 18 1993-06-30 14 1993-12-31 27 1994-06-30 22 1994-12-31 28 1995-06-30 45 1995-12-31 50 1996-06-30 40 1996-12-31 51 1997-06-30 58 1997-12-31 39 1998-06-30 35 1998-12-31 25 1999-06-30 33