Bi-annual US dollars 1987-06-30 319 1987-12-31 323 1988-06-30 391 1988-12-31 550 1989-06-30 498 1989-12-31 635 1990-06-30 443 1990-12-31 365 1991-06-30 370 1991-12-31 351 1992-06-30 415 1992-12-31 570 1993-06-30 887 1993-12-31 925 1994-06-30 894 1994-12-31 912 1995-06-30 948 1995-12-31 1168 1996-06-30 968 1996-12-31 943 1997-06-30 576 1997-12-31 239 1998-06-30 1341 1998-12-31 820 1999-06-30 402