Bi-annual	US dollars
1987-06-30	850
1987-12-31	872
1988-06-30	621
1988-12-31	577
1989-06-30	600
1989-12-31	564
1990-06-30	541
1990-12-31	546
1991-06-30	488
1991-12-31	603
1992-06-30	649
1992-12-31	438
1993-06-30	648
1993-12-31	532
1994-06-30	776
1994-12-31	942
1995-06-30	924
1995-12-31	1064
1996-06-30	1123
1996-12-31	1501
1997-06-30	1540
1997-12-31	1579
1998-06-30	2281
1998-12-31	2543
1999-06-30	2882