Bi-annual	US dollars
1987-06-30	9365
1987-12-31	9878
1988-06-30	8672
1988-12-31	10848
1989-06-30	6167
1989-12-31	6458
1990-06-30	5511
1990-12-31	2879
1991-06-30	2508
1991-12-31	3592
1992-06-30	4388
1992-12-31	4184
1993-06-30	4937
1993-12-31	5325
1994-06-30	6605
1994-12-31	3758
1995-06-30	6162
1995-12-31	5088
1996-06-30	4359
1996-12-31	3978
1997-06-30	5453
1997-12-31	5933
1998-06-30	4668
1998-12-31	4626
1999-06-30	4518