Bi-annual US dollars 1987-06-30 105 1987-12-31 96 1988-06-30 140 1988-12-31 165 1989-06-30 200 1989-12-31 164 1990-06-30 105 1990-12-31 156 1991-06-30 122 1991-12-31 120 1992-06-30 124 1992-12-31 130 1993-06-30 41 1993-12-31 38 1994-06-30 37 1994-12-31 28 1995-06-30 21 1995-12-31 33 1996-06-30 31 1996-12-31 29 1997-06-30 27 1997-12-31 26 1998-06-30 52 1998-12-31 82 1999-06-30 73