Bi-annual	US dollars
1987-06-30	787
1987-12-31	881
1988-06-30	786
1988-12-31	781
1989-06-30	777
1989-12-31	795
1990-06-30	800
1990-12-31	587
1991-06-30	736
1991-12-31	827
1992-06-30	845
1992-12-31	773
1993-06-30	656
1993-12-31	633
1994-06-30	685
1994-12-31	735
1995-06-30	681
1995-12-31	733
1996-06-30	670
1996-12-31	621
1997-06-30	489
1997-12-31	503
1998-06-30	574
1998-12-31	498
1999-06-30	501