Bi-annual	US dollars
1987-06-30	2632
1987-12-31	2442
1988-06-30	1607
1988-12-31	1620
1989-06-30	1673
1989-12-31	1643
1990-06-30	1671
1990-12-31	1522
1991-06-30	1414
1991-12-31	1522
1992-06-30	1562
1992-12-31	1851
1993-06-30	1723
1993-12-31	1586
1994-06-30	1668
1994-12-31	1253
1995-06-30	819
1995-12-31	1426
1996-06-30	1961
1996-12-31	1960
1997-06-30	2623
1997-12-31	1673
1998-06-30	2384
1998-12-31	3945
1999-06-30	2752