Bi-annual	US dollars
1987-06-30	3806
1987-12-31	3523
1988-06-30	3189
1988-12-31	3271
1989-06-30	3000
1989-12-31	2182
1990-06-30	1678
1990-12-31	2074
1991-06-30	1789
1991-12-31	1759
1992-06-30	1619
1992-12-31	1454
1993-06-30	1834
1993-12-31	1605
1994-06-30	1627
1994-12-31	1671
1995-06-30	1812
1995-12-31	1678
1996-06-30	1670
1996-12-31	1755
1997-06-30	1840
1997-12-31	2443
1998-06-30	2386
1998-12-31	2751
1999-06-30	3594