Bi-annual US dollars 1987-06-30 106 1987-12-31 121 1988-06-30 142 1988-12-31 130 1989-06-30 104 1989-12-31 139 1990-06-30 108 1990-12-31 137 1991-06-30 126 1991-12-31 149 1992-06-30 337 1992-12-31 274 1993-06-30 330 1993-12-31 287 1994-06-30 295 1994-12-31 166 1995-06-30 196 1995-12-31 247 1996-06-30 235 1996-12-31 324 1997-06-30 462 1997-12-31 219 1998-06-30 222 1998-12-31 98 1999-06-30 90