Bi-annual US dollars 1987-06-30 152 1987-12-31 77 1988-06-30 125 1988-12-31 83 1989-06-30 109 1989-12-31 105 1990-06-30 85 1990-12-31 129 1991-06-30 148 1991-12-31 202 1992-06-30 167 1992-12-31 264 1993-06-30 176 1993-12-31 368 1994-06-30 573 1994-12-31 427 1995-06-30 690 1995-12-31 285 1996-06-30 267 1996-12-31 363 1997-06-30 418 1997-12-31 352 1998-06-30 510 1998-12-31 238 1999-06-30 200