Bi-annual US dollars 1987-06-30 97 1987-12-31 117 1988-06-30 131 1988-12-31 121 1989-06-30 175 1989-12-31 195 1990-06-30 204 1990-12-31 208 1991-06-30 182 1991-12-31 192 1992-06-30 221 1992-12-31 205 1993-06-30 285 1993-12-31 160 1994-06-30 222 1994-12-31 280 1995-06-30 223 1995-12-31 254 1996-06-30 207 1996-12-31 164 1997-06-30 303 1997-12-31 329 1998-06-30 492 1998-12-31 303 1999-06-30 216