Bi-annual US dollars 1987-06-30 24 1987-12-31 32 1988-06-30 24 1988-12-31 22 1989-06-30 14 1989-12-31 10 1990-06-30 12 1990-12-31 15 1991-06-30 15 1991-12-31 7 1992-06-30 25 1992-12-31 23 1993-06-30 39 1993-12-31 34 1994-06-30 43 1994-12-31 31 1995-06-30 24 1995-12-31 48 1996-06-30 39 1996-12-31 294 1997-06-30 388 1997-12-31 123 1998-06-30 155 1998-12-31 186 1999-06-30 104