Bi-annual	US dollars
1987-06-30	2925
1987-12-31	2893
1988-06-30	2592
1988-12-31	2531
1989-06-30	2273
1989-12-31	2499
1990-06-30	2442
1990-12-31	2472
1991-06-30	2298
1991-12-31	2684
1992-06-30	2737
1992-12-31	2648
1993-06-30	4692
1993-12-31	5430
1994-06-30	6244
1994-12-31	7115
1995-06-30	8159
1995-12-31	9227
1996-06-30	10891
1996-12-31	12222
1997-06-30	14260
1997-12-31	15871
1998-06-30	15226
1998-12-31	14550
1999-06-30	13433