Bi-annual US dollars 1987-06-30 90 1987-12-31 145 1988-06-30 210 1988-12-31 260 1989-06-30 206 1989-12-31 163 1990-06-30 113 1990-12-31 127 1991-06-30 112 1991-12-31 110 1992-06-30 89 1992-12-31 67 1993-06-30 95 1993-12-31 118 1994-06-30 159 1994-12-31 116 1995-06-30 153 1995-12-31 78 1996-06-30 210 1996-12-31 240 1997-06-30 155 1997-12-31 89 1998-06-30 83 1998-12-31 102 1999-06-30 77