Bi-annual	US dollars
1987-06-30	1087
1987-12-31	1266
1988-06-30	1289
1988-12-31	1647
1989-06-30	1333
1989-12-31	1777
1990-06-30	1659
1990-12-31	2038
1991-06-30	2241
1991-12-31	2376
1992-06-30	2409
1992-12-31	2003
1993-06-30	2060
1993-12-31	1738
1994-06-30	1954
1994-12-31	1480
1995-06-30	2558
1995-12-31	2628
1996-06-30	1889
1996-12-31	3354
1997-06-30	3319
1997-12-31	3707
1998-06-30	3510
1998-12-31	4721
1999-06-30	5137