Bi-annual US dollars 1987-06-30 60 1987-12-31 45 1988-06-30 56 1988-12-31 69 1989-06-30 68 1989-12-31 160 1990-06-30 215 1990-12-31 228 1991-06-30 285 1991-12-31 280 1992-06-30 274 1992-12-31 138 1993-06-30 207 1993-12-31 183 1994-06-30 204 1994-12-31 263 1995-06-30 327 1995-12-31 250 1996-06-30 204 1996-12-31 193 1997-06-30 215 1997-12-31 183 1998-06-30 200 1998-12-31 339 1999-06-30 129