Bi-annual US dollars 1987-06-30 493 1987-12-31 464 1988-06-30 426 1988-12-31 425 1989-06-30 307 1989-12-31 308 1990-06-30 267 1990-12-31 266 1991-06-30 203 1991-12-31 312 1992-06-30 240 1992-12-31 208 1993-06-30 381 1993-12-31 469 1994-06-30 404 1994-12-31 565 1995-06-30 487 1995-12-31 975 1996-06-30 580 1996-12-31 620 1997-06-30 878 1997-12-31 961 1998-06-30 428 1998-12-31 185 1999-06-30 213