Bi-annual US dollars 1987-06-30 66 1987-12-31 15 1988-06-30 72 1988-12-31 110 1989-06-30 11 1989-12-31 15 1990-06-30 16 1990-12-31 29 1991-06-30 34 1991-12-31 22 1992-06-30 23 1992-12-31 14 1993-06-30 3 1993-12-31 1 1994-06-30 74 1994-12-31 174 1995-06-30 129 1995-12-31 157 1996-06-30 90 1996-12-31 68 1997-06-30 83 1997-12-31 35 1998-06-30 50 1998-12-31 25 1999-06-30 16