Bi-annual US dollars 1987-06-30 71 1987-12-31 89 1988-06-30 43 1988-12-31 49 1989-06-30 81 1989-12-31 52 1990-06-30 89 1990-12-31 81 1991-06-30 55 1991-12-31 77 1992-06-30 82 1992-12-31 120 1993-06-30 158 1993-12-31 140 1994-06-30 113 1994-12-31 127 1995-06-30 169 1995-12-31 124 1996-06-30 138 1996-12-31 149 1997-06-30 140 1997-12-31 156 1998-06-30 130 1998-12-31 141 1999-06-30 147