Bi-annual US dollars 1987-06-30 572 1987-12-31 470 1988-06-30 440 1988-12-31 405 1989-06-30 352 1989-12-31 348 1990-06-30 394 1990-12-31 106 1991-06-30 96 1991-12-31 114 1992-06-30 160 1992-12-31 188 1993-06-30 162 1993-12-31 217 1994-06-30 244 1994-12-31 255 1995-06-30 181 1995-12-31 219 1996-06-30 163 1996-12-31 159 1997-06-30 125 1997-12-31 138 1998-06-30 292 1998-12-31 359 1999-06-30 421