Bi-annual US dollars 1987-06-30 79 1987-12-31 77 1988-06-30 53 1988-12-31 90 1989-06-30 166 1989-12-31 155 1990-06-30 209 1990-12-31 309 1991-06-30 170 1991-12-31 170 1992-06-30 228 1992-12-31 205 1993-06-30 227 1993-12-31 117 1994-06-30 247 1994-12-31 197 1995-06-30 186 1995-12-31 157 1996-06-30 157 1996-12-31 86 1997-06-30 195 1997-12-31 109 1998-06-30 178 1998-12-31 186 1999-06-30 230