Bi-annual US dollars 1987-06-30 73 1987-12-31 36 1988-06-30 15 1988-12-31 56 1989-06-30 133 1989-12-31 23 1990-06-30 103 1990-12-31 79 1991-06-30 16 1991-12-31 82 1992-06-30 29 1992-12-31 129 1993-06-30 47 1993-12-31 15 1994-06-30 8 1994-12-31 16 1995-06-30 16 1995-12-31 42 1996-06-30 51 1996-12-31 10 1997-06-30 0 1997-12-31 2 1998-06-30 5 1998-12-31 13 1999-06-30 11