Bi-annual	US dollars
1987-06-30	3054
1987-12-31	3812
1988-06-30	3566
1988-12-31	3140
1989-06-30	3240
1989-12-31	3172
1990-06-30	3650
1990-12-31	4069
1991-06-30	3627
1991-12-31	4107
1992-06-30	4230
1992-12-31	5039
1993-06-30	6752
1993-12-31	6747
1994-06-30	8903
1994-12-31	10781
1995-06-30	12879
1995-12-31	14482
1996-06-30	15091
1996-12-31	13984
1997-06-30	20211
1997-12-31	29699
1998-06-30	33176
1998-12-31	48607
1999-06-30	48029