Bi-annual US dollars 1987-06-30 27 1987-12-31 30 1988-06-30 24 1988-12-31 16 1989-06-30 28 1989-12-31 21 1990-06-30 61 1990-12-31 77 1991-06-30 156 1991-12-31 166 1992-06-30 179 1992-12-31 262 1993-06-30 362 1993-12-31 411 1994-06-30 340 1994-12-31 424 1995-06-30 487 1995-12-31 842 1996-06-30 909 1996-12-31 769 1997-06-30 554 1997-12-31 433 1998-06-30 283 1998-12-31 170 1999-06-30 155