Bi-annual US dollars 1987-06-30 348 1987-12-31 319 1988-06-30 309 1988-12-31 694 1989-06-30 712 1989-12-31 947 1990-06-30 392 1990-12-31 172 1991-06-30 204 1991-12-31 196 1992-06-30 183 1992-12-31 288 1993-06-30 437 1993-12-31 364 1994-06-30 403 1994-12-31 385 1995-06-30 313 1995-12-31 251 1996-06-30 259 1996-12-31 216 1997-06-30 589 1997-12-31 347 1998-06-30 290 1998-12-31 446 1999-06-30 568