Bi-annual	US dollars
1987-06-30	3589
1987-12-31	3587
1988-06-30	3580
1988-12-31	3406
1989-06-30	3705
1989-12-31	3615
1990-06-30	3050
1990-12-31	2715
1991-06-30	2919
1991-12-31	2718
1992-06-30	2853
1992-12-31	3177
1993-06-30	3213
1993-12-31	2717
1994-06-30	2614
1994-12-31	2469
1995-06-30	2404
1995-12-31	2144
1996-06-30	1450
1996-12-31	1644
1997-06-30	1973
1997-12-31	1584
1998-06-30	1562
1998-12-31	1775
1999-06-30	1468