Bi-annual	US dollars
1987-06-30	235
1987-12-31	304
1988-06-30	556
1988-12-31	635
1989-06-30	501
1989-12-31	421
1990-06-30	521
1990-12-31	506
1991-06-30	545
1991-12-31	499
1992-06-30	312
1992-12-31	244
1993-06-30	416
1993-12-31	328
1994-06-30	441
1994-12-31	275
1995-06-30	383
1995-12-31	302
1996-06-30	472
1996-12-31	503
1997-06-30	669
1997-12-31	949
1998-06-30	1042
1998-12-31	1156
1999-06-30	926