Bi-annual US dollars 1987-06-30 95 1987-12-31 94 1988-06-30 92 1988-12-31 81 1989-06-30 88 1989-12-31 110 1990-06-30 136 1990-12-31 272 1991-06-30 389 1991-12-31 459 1992-06-30 333 1992-12-31 880 1993-06-30 762 1993-12-31 706 1994-06-30 525 1994-12-31 2151 1995-06-30 833 1995-12-31 262 1996-06-30 239 1996-12-31 296 1997-06-30 155 1997-12-31 262 1998-06-30 357 1998-12-31 359 1999-06-30 1405