Bi-annual US dollars 1987-06-30 21 1987-12-31 47 1988-06-30 20 1988-12-31 25 1989-06-30 14 1989-12-31 15 1990-06-30 65 1990-12-31 37 1991-06-30 76 1991-12-31 82 1992-06-30 63 1992-12-31 80 1993-06-30 755 1993-12-31 140 1994-06-30 154 1994-12-31 213 1995-06-30 262 1995-12-31 236 1996-06-30 232 1996-12-31 259 1997-06-30 206 1997-12-31 1525 1998-06-30 492 1998-12-31 383 1999-06-30 599