Bi-annual	US dollars
1987-06-30	2064
1987-12-31	2412
1988-06-30	2326
1988-12-31	2394
1989-06-30	2260
1989-12-31	2591
1990-06-30	3035
1990-12-31	3708
1991-06-30	3567
1991-12-31	3913
1992-06-30	3777
1992-12-31	4333
1993-06-30	8640
1993-12-31	9558
1994-06-30	7897
1994-12-31	9027
1995-06-30	8174
1995-12-31	8568
1996-06-30	10607
1996-12-31	12854
1997-06-30	14550
1997-12-31	14946
1998-06-30	22290
1998-12-31	20079
1999-06-30	25593