Bi-annual US dollars 1987-06-30 35 1987-12-31 38 1988-06-30 12 1988-12-31 38 1989-06-30 34 1989-12-31 11 1990-06-30 28 1990-12-31 19 1991-06-30 13 1991-12-31 15 1992-06-30 89 1992-12-31 133 1993-06-30 150 1993-12-31 340 1994-06-30 244 1994-12-31 58 1995-06-30 16 1995-12-31 19 1996-06-30 31 1996-12-31 7 1997-06-30 -37 1997-12-31 3 1998-06-30 10 1998-12-31 22 1999-06-30 20