Bi-annual US dollars 1987-06-30 69 1987-12-31 92 1988-06-30 70 1988-12-31 69 1989-06-30 59 1989-12-31 73 1990-06-30 56 1990-12-31 81 1991-06-30 55 1991-12-31 77 1992-06-30 65 1992-12-31 45 1993-06-30 54 1993-12-31 37 1994-06-30 34 1994-12-31 44 1995-06-30 40 1995-12-31 40 1996-06-30 47 1996-12-31 56 1997-06-30 55 1997-12-31 46 1998-06-30 55 1998-12-31 70 1999-06-30 68