Bi-annual	US dollars
1987-06-30	4707
1987-12-31	4576
1988-06-30	4613
1988-12-31	4366
1989-06-30	3302
1989-12-31	2783
1990-06-30	2102
1990-12-31	1931
1991-06-30	2617
1991-12-31	2695
1992-06-30	3247
1992-12-31	2174
1993-06-30	3154
1993-12-31	3995
1994-06-30	4427
1994-12-31	4246
1995-06-30	4295
1995-12-31	4625
1996-06-30	4846
1996-12-31	5581
1997-06-30	4523
1997-12-31	4617
1998-06-30	4717
1998-12-31	5361
1999-06-30	5822