Bi-annual	US dollars
1987-06-30	950
1987-12-31	913
1988-06-30	1074
1988-12-31	1040
1989-06-30	1265
1989-12-31	1301
1990-06-30	1563
1990-12-31	816
1991-06-30	600
1991-12-31	643
1992-06-30	632
1992-12-31	668
1993-06-30	834
1993-12-31	749
1994-06-30	940
1994-12-31	516
1995-06-30	436
1995-12-31	423
1996-06-30	542
1996-12-31	383
1997-06-30	705
1997-12-31	893
1998-06-30	1279
1998-12-31	810
1999-06-30	754