Bi-annual US dollars 1987-06-30 111 1987-12-31 9 1988-06-30 17 1988-12-31 38 1989-06-30 33 1989-12-31 27 1990-06-30 26 1990-12-31 21 1991-06-30 97 1991-12-31 52 1992-06-30 59 1992-12-31 23 1993-06-30 290 1993-12-31 64 1994-06-30 49 1994-12-31 80 1995-06-30 56 1995-12-31 101 1996-06-30 204 1996-12-31 180 1997-06-30 256 1997-12-31 196 1998-06-30 338 1998-12-31 221 1999-06-30 224