Bi-annual	US dollars
1987-06-30	4284
1987-12-31	3555
1988-06-30	3198
1988-12-31	2790
1989-06-30	2328
1989-12-31	2324
1990-06-30	2157
1990-12-31	1601
1991-06-30	1772
1991-12-31	1688
1992-06-30	1895
1992-12-31	1900
1993-06-30	1961
1993-12-31	1655
1994-06-30	1855
1994-12-31	1801
1995-06-30	1820
1995-12-31	2045
1996-06-30	1493
1996-12-31	2512
1997-06-30	2778
1997-12-31	2172
1998-06-30	1806
1998-12-31	1779
1999-06-30	1604