Bi-annual	US dollars
1987-06-30	2724
1987-12-31	2240
1988-06-30	2215
1988-12-31	1676
1989-06-30	1530
1989-12-31	1219
1990-06-30	1580
1990-12-31	1715
1991-06-30	1670
1991-12-31	1453
1992-06-30	1543
1992-12-31	1851
1993-06-30	1525
1993-12-31	1318
1994-06-30	1628
1994-12-31	1480
1995-06-30	1639
1995-12-31	1699
1996-06-30	1039
1996-12-31	1359
1997-06-30	1575
1997-12-31	1622
1998-06-30	1055
1998-12-31	978
1999-06-30	743