Bi-annual US dollars 1987-06-30 63 1987-12-31 23 1988-06-30 10 1988-12-31 24 1989-06-30 19 1989-12-31 15 1990-06-30 24 1990-12-31 27 1991-06-30 39 1991-12-31 41 1992-06-30 44 1992-12-31 29 1993-06-30 33 1993-12-31 3 1994-06-30 3 1994-12-31 0 1995-06-30 0 1995-12-31 0 1996-06-30 3 1996-12-31 9 1997-06-30 7 1997-12-31 10 1998-06-30 27 1998-12-31 25 1999-06-30 19