Bi-annual	US dollars
1987-06-30	555
1987-12-31	568
1988-06-30	573
1988-12-31	597
1989-06-30	589
1989-12-31	650
1990-06-30	588
1990-12-31	617
1991-06-30	529
1991-12-31	577
1992-06-30	615
1992-12-31	592
1993-06-30	774
1993-12-31	758
1994-06-30	830
1994-12-31	959
1995-06-30	904
1995-12-31	901
1996-06-30	1035
1996-12-31	1075
1997-06-30	1126
1997-12-31	1285
1998-06-30	1652
1998-12-31	1544
1999-06-30	1277