Bi-annual US dollars 1987-06-30 223 1987-12-31 208 1988-06-30 167 1988-12-31 246 1989-06-30 285 1989-12-31 297 1990-06-30 368 1990-12-31 394 1991-06-30 248 1991-12-31 256 1992-06-30 308 1992-12-31 312 1993-06-30 365 1993-12-31 380 1994-06-30 377 1994-12-31 447 1995-06-30 441 1995-12-31 405 1996-06-30 514 1996-12-31 616 1997-06-30 807 1997-12-31 826 1998-06-30 1062 1998-12-31 822 1999-06-30 806