Bi-annual	US dollars
1987-06-30	2133
1987-12-31	2042
1988-06-30	1924
1988-12-31	1643
1989-06-30	1983
1989-12-31	1883
1990-06-30	1952
1990-12-31	1802
1991-06-30	1990
1991-12-31	2867
1992-06-30	3220
1992-12-31	1971
1993-06-30	3649
1993-12-31	3597
1994-06-30	3460
1994-12-31	3645
1995-06-30	3336
1995-12-31	3203
1996-06-30	3724
1996-12-31	3325
1997-06-30	727
1997-12-31	268
1998-06-30	3026
1998-12-31	1770
1999-06-30	3089