Bi-annual US dollars 1987-06-30 45 1987-12-31 18 1988-06-30 38 1988-12-31 226 1989-06-30 55 1989-12-31 98 1990-06-30 26 1990-12-31 33 1991-06-30 97 1991-12-31 187 1992-06-30 221 1992-12-31 165 1993-06-30 170 1993-12-31 350 1994-06-30 333 1994-12-31 311 1995-06-30 194 1995-12-31 234 1996-06-30 207 1996-12-31 236 1997-06-30 289 1997-12-31 267 1998-06-30 305 1998-12-31 198 1999-06-30 147