| Date | Acquired | Amount |
|---|---|---|
| Jul 15, 2008 |
|
Undisclosed amount |
| May 15, 2007 |
|
$ 749,000,000 |
| Feb 28, 2007 |
|
Undisclosed amount |
| Aug 30, 2001 |
|
$ 23,000,000,000 |
| Aug 01, 1998 |
|
Undisclosed amount |
