Bi-annual US dollars 1987-06-30 26 1987-12-31 34 1988-06-30 32 1988-12-31 38 1989-06-30 31 1989-12-31 29 1990-06-30 26 1990-12-31 27 1991-06-30 16 1991-12-31 15 1992-06-30 13 1992-12-31 8 1993-06-30 6 1993-12-31 1 1994-06-30 2 1994-12-31 2 1995-06-30 2 1995-12-31 3 1996-06-30 9 1996-12-31 2 1997-06-30 2 1997-12-31 3 1998-06-30 3 1998-12-31 2 1999-06-30 2