Bi-annual US dollars 1987-06-30 47 1987-12-31 58 1988-06-30 94 1988-12-31 110 1989-06-30 150 1989-12-31 123 1990-06-30 140 1990-12-31 118 1991-06-30 149 1991-12-31 269 1992-06-30 126 1992-12-31 62 1993-06-30 122 1993-12-31 235 1994-06-30 245 1994-12-31 401 1995-06-30 541 1995-12-31 482 1996-06-30 493 1996-12-31 555 1997-06-30 601 1997-12-31 392 1998-06-30 232 1998-12-31 281 1999-06-30 300