Bi-annual	US dollars
1987-06-30	3838
1987-12-31	4380
1988-06-30	5633
1988-12-31	5659
1989-06-30	5044
1989-12-31	4460
1990-06-30	3914
1990-12-31	3616
1991-06-30	3334
1991-12-31	4679
1992-06-30	6449
1992-12-31	5805
1993-06-30	8049
1993-12-31	8522
1994-06-30	8756
1994-12-31	9828
1995-06-30	9790
1995-12-31	9308
1996-06-30	10568
1996-12-31	11371
1997-06-30	11011
1997-12-31	12068
1998-06-30	16331
1998-12-31	17272
1999-06-30	17819