Bi-annual US dollars 1987-06-30 168 1987-12-31 164 1988-06-30 130 1988-12-31 85 1989-06-30 59 1989-12-31 76 1990-06-30 82 1990-12-31 41 1991-06-30 55 1991-12-31 56 1992-06-30 78 1992-12-31 77 1993-06-30 158 1993-12-31 254 1994-06-30 127 1994-12-31 228 1995-06-30 205 1995-12-31 174 1996-06-30 160 1996-12-31 161 1997-06-30 120 1997-12-31 278 1998-06-30 295 1998-12-31 225 1999-06-30 172