Bi-annual	US dollars
1987-06-30	2000
1987-12-31	1949
1988-06-30	1656
1988-12-31	1188
1989-06-30	1412
1989-12-31	1248
1990-06-30	1449
1990-12-31	1584
1991-06-30	2001
1991-12-31	2058
1992-06-30	2384
1992-12-31	2198
1993-06-30	1434
1993-12-31	2742
1994-06-30	3086
1994-12-31	3506
1995-06-30	4060
1995-12-31	4661
1996-06-30	5357
1996-12-31	6422
1997-06-30	6886
1997-12-31	7940
1998-06-30	7059
1998-12-31	6250
1999-06-30	5990