Bi-annual US dollars 1987-06-30 766 1987-12-31 879 1988-06-30 1180 1988-12-31 720 1989-06-30 1048 1989-12-31 1090 1990-06-30 1350 1990-12-31 1387 1991-06-30 1203 1991-12-31 1281 1992-06-30 1372 1992-12-31 809 1993-06-30 606 1993-12-31 392 1994-06-30 574 1994-12-31 462 1995-06-30 598 1995-12-31 291 1996-06-30 339 1996-12-31 370 1997-06-30 286 1997-12-31 410 1998-06-30 298 1998-12-31 381 1999-06-30 415