Bi-annual US dollars 1987-06-30 11 1987-12-31 13 1988-06-30 10 1988-12-31 7 1989-06-30 6 1989-12-31 3 1990-06-30 0 1990-12-31 0 1991-06-30 0 1991-12-31 0 1992-06-30 0 1992-12-31 3 1993-06-30 3 1993-12-31 24 1994-06-30 25 1994-12-31 25 1995-06-30 22 1995-12-31 26 1996-06-30 19 1996-12-31 19 1997-06-30 17 1997-12-31 20 1998-06-30 28 1998-12-31 23 1999-06-30 19