Bi-annual US dollars 1987-06-30 555 1987-12-31 472 1988-06-30 640 1988-12-31 448 1989-06-30 670 1989-12-31 293 1990-06-30 215 1990-12-31 581 1991-06-30 293 1991-12-31 217 1992-06-30 266 1992-12-31 332 1993-06-30 372 1993-12-31 371 1994-06-30 386 1994-12-31 283 1995-06-30 278 1995-12-31 347 1996-06-30 493 1996-12-31 464 1997-06-30 378 1997-12-31 513 1998-06-30 697 1998-12-31 383 1999-06-30 628