Bi-annual US dollars 1987-06-30 498 1987-12-31 560 1988-06-30 379 1988-12-31 400 1989-06-30 372 1989-12-31 342 1990-06-30 375 1990-12-31 428 1991-06-30 517 1991-12-31 685 1992-06-30 683 1992-12-31 774 1993-06-30 822 1993-12-31 508 1994-06-30 545 1994-12-31 630 1995-06-30 531 1995-12-31 606 1996-06-30 538 1996-12-31 563 1997-06-30 1176 1997-12-31 1343 1998-06-30 1891 1998-12-31 2045 1999-06-30 1217