Bi-annual US dollars 1987-06-30 97 1987-12-31 77 1988-06-30 70 1988-12-31 65 1989-06-30 56 1989-12-31 71 1990-06-30 35 1990-12-31 23 1991-06-30 26 1991-12-31 19 1992-06-30 25 1992-12-31 17 1993-06-30 20 1993-12-31 18 1994-06-30 28 1994-12-31 33 1995-06-30 30 1995-12-31 33 1996-06-30 16 1996-12-31 68 1997-06-30 113 1997-12-31 54 1998-06-30 13 1998-12-31 23 1999-06-30 24