Bi-annual	US dollars
1987-06-30	35032
1987-12-31	35447
1988-06-30	34257
1988-12-31	37668
1989-06-30	34507
1989-12-31	33614
1990-06-30	30438
1990-12-31	30540
1991-06-30	29847
1991-12-31	30828
1992-06-30	30931
1992-12-31	28314
1993-06-30	29032
1993-12-31	32699
1994-06-30	30867
1994-12-31	33188
1995-06-30	33024
1995-12-31	33999
1996-06-30	33328
1996-12-31	38628
1997-06-30	40768
1997-12-31	44785
1998-06-30	51124
1998-12-31	52003
1999-06-30	51292