Bi-annual US dollars 1987-06-30 1017 1987-12-31 1334 1988-06-30 1351 1988-12-31 1828 1989-06-30 1166 1989-12-31 627 1990-06-30 487 1990-12-31 727 1991-06-30 475 1991-12-31 622 1992-06-30 561 1992-12-31 476 1993-06-30 399 1993-12-31 368 1994-06-30 310 1994-12-31 289 1995-06-30 275 1995-12-31 223 1996-06-30 291 1996-12-31 286 1997-06-30 230 1997-12-31 160 1998-06-30 203 1998-12-31 205 1999-06-30 159