Bi-annual US dollars 1987-06-30 216 1987-12-31 164 1988-06-30 109 1988-12-31 139 1989-06-30 85 1989-12-31 150 1990-06-30 117 1990-12-31 108 1991-06-30 73 1991-12-31 125 1992-06-30 131 1992-12-31 89 1993-06-30 117 1993-12-31 106 1994-06-30 361 1994-12-31 374 1995-06-30 259 1995-12-31 288 1996-06-30 306 1996-12-31 248 1997-06-30 213 1997-12-31 270 1998-06-30 358 1998-12-31 419 1999-06-30 552