Bi-annual US dollars 1987-06-30 82 1987-12-31 89 1988-06-30 99 1988-12-31 110 1989-06-30 104 1989-12-31 116 1990-06-30 120 1990-12-31 149 1991-06-30 136 1991-12-31 185 1992-06-30 219 1992-12-31 217 1993-06-30 239 1993-12-31 214 1994-06-30 364 1994-12-31 335 1995-06-30 388 1995-12-31 354 1996-06-30 379 1996-12-31 438 1997-06-30 419 1997-12-31 517 1998-06-30 532 1998-12-31 406 1999-06-30 363