Bi-annual	US dollars
1987-06-30	3957
1987-12-31	3808
1988-06-30	3877
1988-12-31	3811
1989-06-30	3220
1989-12-31	3177
1990-06-30	2796
1990-12-31	2576
1991-06-30	3084
1991-12-31	3252
1992-06-30	4232
1992-12-31	3866
1993-06-30	5729
1993-12-31	4684
1994-06-30	5873
1994-12-31	6712
1995-06-30	8477
1995-12-31	9297
1996-06-30	9145
1996-12-31	9466
1997-06-30	9659
1997-12-31	11228
1998-06-30	13005
1998-12-31	11794
1999-06-30	12010