Bi-annual	US dollars
1987-06-30	7206
1987-12-31	6805
1988-06-30	7832
1988-12-31	6207
1989-06-30	6267
1989-12-31	6419
1990-06-30	5497
1990-12-31	5765
1991-06-30	4839
1991-12-31	5168
1992-06-30	5062
1992-12-31	4483
1993-06-30	13928
1993-12-31	11342
1994-06-30	12440
1994-12-31	11646
1995-06-30	12031
1995-12-31	13548
1996-06-30	16533
1996-12-31	17456
1997-06-30	21161
1997-12-31	21813
1998-06-30	20386
1998-12-31	16530
1999-06-30	15251