Bi-annual US dollars 1987-06-30 156 1987-12-31 200 1988-06-30 172 1988-12-31 177 1989-06-30 141 1989-12-31 123 1990-06-30 117 1990-12-31 98 1991-06-30 154 1991-12-31 196 1992-06-30 213 1992-12-31 297 1993-06-30 300 1993-12-31 140 1994-06-30 60 1994-12-31 58 1995-06-30 49 1995-12-31 43 1996-06-30 33 1996-12-31 15 1997-06-30 30 1997-12-31 7 1998-06-30 17 1998-12-31 12 1999-06-30 17