Bi-annual	US dollars
1987-06-30	11500
1987-12-31	11909
1988-06-30	12051
1988-12-31	13347
1989-06-30	11253
1989-12-31	10035
1990-06-30	7738
1990-12-31	5985
1991-06-30	6736
1991-12-31	5297
1992-06-30	5125
1992-12-31	4628
1993-06-30	3976
1993-12-31	4687
1994-06-30	4389
1994-12-31	3573
1995-06-30	3804
1995-12-31	3596
1996-06-30	3207
1996-12-31	3239
1997-06-30	3743
1997-12-31	4270
1998-06-30	4685
1998-12-31	4811
1999-06-30	4629