Bi-annual US dollars 1987-06-30 9109 1987-12-31 7757 1988-06-30 8087 1988-12-31 8429 1989-06-30 6029 1989-12-31 5595 1990-06-30 5528 1990-12-31 3919 1991-06-30 4081 1991-12-31 3127 1992-06-30 3534 1992-12-31 3162 1993-06-30 3610 1993-12-31 4375 1994-06-30 5694 1994-12-31 5062 1995-06-30 12592 1995-12-31 3158 1996-06-30 4184 1996-12-31 5513 1997-06-30 5267 1997-12-31 4444 1998-06-30 6489 1998-12-31 5754 1999-06-30 4231