Bi-annual US dollars 1987-06-30 555 1987-12-31 721 1988-06-30 723 1988-12-31 725 1989-06-30 471 1989-12-31 256 1990-06-30 263 1990-12-31 251 1991-06-30 379 1991-12-31 417 1992-06-30 405 1992-12-31 318 1993-06-30 372 1993-12-31 358 1994-06-30 356 1994-12-31 307 1995-06-30 293 1995-12-31 262 1996-06-30 98 1996-12-31 115 1997-06-30 146 1997-12-31 117 1998-06-30 325 1998-12-31 433 1999-06-30 468