Bi-annual US dollars 1987-06-30 47 1987-12-31 17 1988-06-30 19 1988-12-31 11 1989-06-30 11 1989-12-31 10 1990-06-30 16 1990-12-31 17 1991-06-30 13 1991-12-31 19 1992-06-30 13 1992-12-31 11 1993-06-30 12 1993-12-31 9 1994-06-30 11 1994-12-31 9 1995-06-30 8 1995-12-31 8 1996-06-30 8 1996-12-31 15 1997-06-30 10 1997-12-31 21 1998-06-30 15 1998-12-31 23 1999-06-30 14