Bi-annual US dollars 1987-06-30 1779 1987-12-31 2046 1988-06-30 1799 1988-12-31 2030 1989-06-30 2052 1989-12-31 1661 1990-06-30 141 1990-12-31 156 1991-06-30 186 1991-12-31 459 1992-06-30 617 1992-12-31 845 1993-06-30 1403 1993-12-31 1593 1994-06-30 1384 1994-12-31 1690 1995-06-30 1495 1995-12-31 1307 1996-06-30 1130 1996-12-31 1245 1997-06-30 1338 1997-12-31 1951 1998-06-30 1604 1998-12-31 1453 1999-06-30 1473