Bi-annual	US dollars
1987-06-30	566
1987-12-31	619
1988-06-30	559
1988-12-31	539
1989-06-30	552
1989-12-31	589
1990-06-30	598
1990-12-31	631
1991-06-30	611
1991-12-31	637
1992-06-30	676
1992-12-31	626
1993-06-30	687
1993-12-31	1058
1994-06-30	759
1994-12-31	640
1995-06-30	676
1995-12-31	816
1996-06-30	889
1996-12-31	1044
1997-06-30	1231
1997-12-31	1374
1998-06-30	1529
1998-12-31	2489
1999-06-30	1757