Bi-annual US dollars 1987-06-30 232 1987-12-31 274 1988-06-30 244 1988-12-31 213 1989-06-30 285 1989-12-31 223 1990-06-30 215 1990-12-31 264 1991-06-30 318 1991-12-31 205 1992-06-30 540 1992-12-31 382 1993-06-30 81 1993-12-31 96 1994-06-30 73 1994-12-31 114 1995-06-30 215 1995-12-31 126 1996-06-30 238 1996-12-31 137 1997-06-30 28 1997-12-31 54 1998-06-30 268 1998-12-31 40 1999-06-30 407