Bi-annual	US dollars
1987-06-30	1917
1987-12-31	3010
1988-06-30	2753
1988-12-31	3153
1989-06-30	2118
1989-12-31	2677
1990-06-30	2356
1990-12-31	2518
1991-06-30	2241
1991-12-31	2596
1992-06-30	3737
1992-12-31	2527
1993-06-30	4285
1993-12-31	3373
1994-06-30	4543
1994-12-31	3106
1995-06-30	4585
1995-12-31	3848
1996-06-30	5590
1996-12-31	4266
1997-06-30	4236
1997-12-31	5920
1998-06-30	6399
1998-12-31	6995
1999-06-30	8242