Bi-annual US dollars 1987-06-30 29 1987-12-31 25 1988-06-30 46 1988-12-31 36 1989-06-30 16 1989-12-31 19 1990-06-30 9 1990-12-31 23 1991-06-30 10 1991-12-31 54 1992-06-30 38 1992-12-31 67 1993-06-30 158 1993-12-31 136 1994-06-30 79 1994-12-31 97 1995-06-30 126 1995-12-31 90 1996-06-30 75 1996-12-31 75 1997-06-30 72 1997-12-31 30 1998-06-30 67 1998-12-31 73 1999-06-30 79