Bi-annual US dollars 1987-06-30 184 1987-12-31 217 1988-06-30 249 1988-12-31 318 1989-06-30 512 1989-12-31 134 1990-06-30 326 1990-12-31 232 1991-06-30 167 1991-12-31 170 1992-06-30 322 1992-12-31 479 1993-06-30 131 1993-12-31 325 1994-06-30 298 1994-12-31 324 1995-06-30 308 1995-12-31 250 1996-06-30 354 1996-12-31 82 1997-06-30 146 1997-12-31 179 1998-06-30 322 1998-12-31 428 1999-06-30 159