Bi-annual	US dollars
1987-06-30	2746
1987-12-31	2281
1988-06-30	2514
1988-12-31	2016
1989-06-30	2310
1989-12-31	1848
1990-06-30	2463
1990-12-31	2663
1991-06-30	3052
1991-12-31	3381
1992-06-30	4306
1992-12-31	4039
1993-06-30	6635
1993-12-31	8534
1994-06-30	8810
1994-12-31	9193
1995-06-30	10440
1995-12-31	12903
1996-06-30	13293
1996-12-31	14602
1997-06-30	17015
1997-12-31	17605
1998-06-30	15304
1998-12-31	13435
1999-06-30	11153