Bi-annual US dollars 1987-06-30 68 1987-12-31 66 1988-06-30 242 1988-12-31 125 1989-06-30 203 1989-12-31 65 1990-06-30 47 1990-12-31 46 1991-06-30 62 1991-12-31 24 1992-06-30 36 1992-12-31 67 1993-06-30 75 1993-12-31 78 1994-06-30 91 1994-12-31 75 1995-06-30 59 1995-12-31 42 1996-06-30 36 1996-12-31 46 1997-06-30 47 1997-12-31 324 1998-06-30 148 1998-12-31 82 1999-06-30 6