Bi-annual US dollars 1987-06-30 31 1987-12-31 58 1988-06-30 34 1988-12-31 16 1989-06-30 22 1989-12-31 26 1990-06-30 61 1990-12-31 31 1991-06-30 49 1991-12-31 21 1992-06-30 40 1992-12-31 103 1993-06-30 56 1993-12-31 12 1994-06-30 128 1994-12-31 191 1995-06-30 151 1995-12-31 146 1996-06-30 59 1996-12-31 62 1997-06-30 45 1997-12-31 71 1998-06-30 112 1998-12-31 22 1999-06-30 120