Bi-annual US dollars 1987-06-30 208 1987-12-31 225 1988-06-30 153 1988-12-31 61 1989-06-30 242 1989-12-31 52 1990-06-30 51 1990-12-31 100 1991-06-30 45 1991-12-31 75 1992-06-30 204 1992-12-31 174 1993-06-30 420 1993-12-31 95 1994-06-30 170 1994-12-31 496 1995-06-30 134 1995-12-31 240 1996-06-30 224 1996-12-31 300 1997-06-30 276 1997-12-31 153 1998-06-30 155 1998-12-31 143 1999-06-30 151