Bi-annual US dollars 1987-06-30 155 1987-12-31 160 1988-06-30 162 1988-12-31 136 1989-06-30 192 1989-12-31 132 1990-06-30 146 1990-12-31 241 1991-06-30 339 1991-12-31 170 1992-06-30 320 1992-12-31 336 1993-06-30 767 1993-12-31 501 1994-06-30 292 1994-12-31 462 1995-06-30 550 1995-12-31 715 1996-06-30 659 1996-12-31 596 1997-06-30 1008 1997-12-31 390 1998-06-30 1069 1998-12-31 1391 1999-06-30 3609