Bi-annual	US dollars
1987-06-30	6505
1987-12-31	11086
1988-06-30	9020
1988-12-31	12895
1989-06-30	7425
1989-12-31	9230
1990-06-30	9780
1990-12-31	12640
1991-06-30	8993
1991-12-31	11707
1992-06-30	6577
1992-12-31	5946
1993-06-30	7013
1993-12-31	5704
1994-06-30	6111
1994-12-31	6354
1995-06-30	6818
1995-12-31	7638
1996-06-30	7994
1996-12-31	11138
1997-06-30	9276
1997-12-31	11145
1998-06-30	10779
1998-12-31	10270
1999-06-30	10885
