Bi-annual US dollars 1987-06-30 674 1987-12-31 759 1988-06-30 665 1988-12-31 465 1989-06-30 606 1989-12-31 540 1990-06-30 603 1990-12-31 629 1991-06-30 809 1991-12-31 773 1992-06-30 976 1992-12-31 918 1993-06-30 1373 1993-12-31 1434 1994-06-30 1415 1994-12-31 1683 1995-06-30 1704 1995-12-31 2002 1996-06-30 2237 1996-12-31 2503 1997-06-30 2747 1997-12-31 3129 1998-06-30 2694 1998-12-31 2371 1999-06-30 2573