Bi-annual	US dollars
1987-06-30	3173
1987-12-31	1644
1988-06-30	1410
1988-12-31	1454
1989-06-30	1319
1989-12-31	1659
1990-06-30	957
1990-12-31	851
1991-06-30	991
1991-12-31	1334
1992-06-30	1667
1992-12-31	1763
1993-06-30	2008
1993-12-31	2770
1994-06-30	3562
1994-12-31	3927
1995-06-30	2918
1995-12-31	2641
1996-06-30	3631
1996-12-31	4275
1997-06-30	3835
1997-12-31	4289
1998-06-30	5025
1998-12-31	5406
1999-06-30	5522