Bi-annual	US dollars
1987-06-30	1337
1987-12-31	1296
1988-06-30	1148
1988-12-31	1204
1989-06-30	1059
1989-12-31	980
1990-06-30	863
1990-12-31	915
1991-06-30	893
1991-12-31	1063
1992-06-30	1132
1992-12-31	1064
1993-06-30	1487
1993-12-31	1778
1994-06-30	1722
1994-12-31	1921
1995-06-30	2515
1995-12-31	2727
1996-06-30	3261
1996-12-31	3833
1997-06-30	4332
1997-12-31	4482
1998-06-30	3962
1998-12-31	3811
1999-06-30	3423