Bi-annual US dollars 1987-06-30 576 1987-12-31 691 1988-06-30 677 1988-12-31 586 1989-06-30 498 1989-12-31 610 1990-06-30 699 1990-12-31 760 1991-06-30 700 1991-12-31 764 1992-06-30 925 1992-12-31 920 1993-06-30 902 1993-12-31 749 1994-06-30 684 1994-12-31 932 1995-06-30 1650 1995-12-31 1456 1996-06-30 1639 1996-12-31 1554 1997-06-30 1248 1997-12-31 1756 1998-06-30 2011 1998-12-31 1631 1999-06-30 2083