Bi-annual	US dollars
1987-06-30	5058
1987-12-31	5214
1988-06-30	5292
1988-12-31	4616
1989-06-30	4147
1989-12-31	4597
1990-06-30	5138
1990-12-31	5659
1991-06-30	4547
1991-12-31	4793
1992-06-30	5108
1992-12-31	4956
1993-06-30	13392
1993-12-31	14119
1994-06-30	13640
1994-12-31	13642
1995-06-30	15914
1995-12-31	19298
1996-06-30	18380
1996-12-31	20464
1997-06-30	21223
1997-12-31	22156
1998-06-30	18996
1998-12-31	19063
1999-06-30	17070