Bi-annual US dollars 1987-06-30 445 1987-12-31 472 1988-06-30 430 1988-12-31 410 1989-06-30 352 1989-12-31 161 1990-06-30 391 1990-12-31 349 1991-06-30 86 1991-12-31 303 1992-06-30 304 1992-12-31 238 1993-06-30 231 1993-12-31 467 1994-06-30 290 1994-12-31 447 1995-06-30 472 1995-12-31 448 1996-06-30 376 1996-12-31 423 1997-06-30 336 1997-12-31 271 1998-06-30 263 1998-12-31 258 1999-06-30 279