Bi-annual US dollars 1987-06-30 61 1987-12-31 64 1988-06-30 70 1988-12-31 60 1989-06-30 33 1989-12-31 47 1990-06-30 37 1990-12-31 33 1991-06-30 26 1991-12-31 30 1992-06-30 17 1992-12-31 15 1993-06-30 18 1993-12-31 18 1994-06-30 14 1994-12-31 33 1995-06-30 30 1995-12-31 36 1996-06-30 51 1996-12-31 74 1997-06-30 62 1997-12-31 38 1998-06-30 55 1998-12-31 67 1999-06-30 57