Bi-annual US dollars 1987-06-30 127 1987-12-31 145 1988-06-30 164 1988-12-31 183 1989-06-30 28 1989-12-31 32 1990-06-30 30 1990-12-31 85 1991-06-30 76 1991-12-31 75 1992-06-30 65 1992-12-31 67 1993-06-30 35 1993-12-31 25 1994-06-30 20 1994-12-31 31 1995-06-30 40 1995-12-31 47 1996-06-30 44 1996-12-31 39 1997-06-30 27 1997-12-31 28 1998-06-30 20 1998-12-31 37 1999-06-30 43