Bi-annual	US dollars
1987-06-30	845
1987-12-31	930
1988-06-30	657
1988-12-31	765
1989-06-30	862
1989-12-31	1092
1990-06-30	1182
1990-12-31	1565
1991-06-30	1354
1991-12-31	1386
1992-06-30	1463
1992-12-31	1641
1993-06-30	2549
1993-12-31	4283
1994-06-30	4111
1994-12-31	5164
1995-06-30	5074
1995-12-31	4842
1996-06-30	6219
1996-12-31	7026
1997-06-30	9516
1997-12-31	9513
1998-06-30	11046
1998-12-31	13816
1999-06-30	22138