Bi-annual US dollars 1987-06-30 8 1987-12-31 2 1988-06-30 17 1988-12-31 13 1989-06-30 14 1989-12-31 16 1990-06-30 2 1990-12-31 12 1991-06-30 19 1991-12-31 26 1992-06-30 23 1992-12-31 12 1993-06-30 47 1993-12-31 7 1994-06-30 8 1994-12-31 9 1995-06-30 6 1995-12-31 6 1996-06-30 14 1996-12-31 14 1997-06-30 13 1997-12-31 12 1998-06-30 37 1998-12-31 23 1999-06-30 35