Bi-annual	US dollars
1987-06-30	890
1987-12-31	883
1988-06-30	715
1988-12-31	539
1989-06-30	519
1989-12-31	585
1990-06-30	588
1990-12-31	415
1991-06-30	495
1991-12-31	441
1992-06-30	546
1992-12-31	689
1993-06-30	728
1993-12-31	763
1994-06-30	512
1994-12-31	756
1995-06-30	558
1995-12-31	533
1996-06-30	600
1996-12-31	570
1997-06-30	582
1997-12-31	721
1998-06-30	879
1998-12-31	1163
1999-06-30	863