Bi-annual US dollars 1987-06-30 44615 1987-12-31 42390 1988-06-30 39581 1988-12-31 40877 1989-06-30 39646 1989-12-31 44423 1990-06-30 44097 1990-12-31 45339 1991-06-30 43463 1991-12-31 46891 1992-06-30 49560 1992-12-31 45489 1993-06-30 62197 1993-12-31 63615 1994-06-30 67756 1994-12-31 83020 1995-06-30 90135 1995-12-31 93335 1996-06-30 108871 1996-12-31 125854 1997-06-30 128823 1997-12-31 159597 1998-06-30 178991 1998-12-31 164818 1999-06-30 163055