Bi-annual US dollars 1987-06-30 35 1987-12-31 40 1988-06-30 36 1988-12-31 36 1989-06-30 45 1989-12-31 34 1990-06-30 37 1990-12-31 37 1991-06-30 29 1991-12-31 35 1992-06-30 36 1992-12-31 35 1993-06-30 33 1993-12-31 33 1994-06-30 37 1994-12-31 36 1995-06-30 38 1995-12-31 37 1996-06-30 34 1996-12-31 34 1997-06-30 33 1997-12-31 31 1998-06-30 33 1998-12-31 33 1999-06-30 28