Bi-annual US dollars 1987-06-30 281 1987-12-31 436 1988-06-30 391 1988-12-31 313 1989-06-30 370 1989-12-31 432 1990-06-30 417 1990-12-31 311 1991-06-30 271 1991-12-31 211 1992-06-30 186 1992-12-31 241 1993-06-30 392 1993-12-31 828 1994-06-30 421 1994-12-31 1173 1995-06-30 498 1995-12-31 667 1996-06-30 576 1996-12-31 550 1997-06-30 645 1997-12-31 1084 1998-06-30 892 1998-12-31 1348 1999-06-30 853