Bi-annual US dollars 1987-06-30 87 1987-12-31 66 1988-06-30 87 1988-12-31 54 1989-06-30 26 1989-12-31 27 1990-06-30 37 1990-12-31 56 1991-06-30 37 1991-12-31 45 1992-06-30 67 1992-12-31 74 1993-06-30 75 1993-12-31 61 1994-06-30 105 1994-12-31 55 1995-06-30 81 1995-12-31 74 1996-06-30 71 1996-12-31 80 1997-06-30 77 1997-12-31 72 1998-06-30 83 1998-12-31 73 1999-06-30 93