| Date | Acquired | Amount |
|---|---|---|
| Oct 19, 2017 |
|
$ 275,000,000 |
| Jul 25, 2016 |
|
$ 725,000,000 |
| Jan 14, 2010 |
|
Undisclosed amount |
| Sep 29, 2005 |
|
$ 1,600,000,000 |
| Aug 08, 2005 |
|
$ 700,000,000 |
| May 22, 2001 |
|
$ 45,000,000 |
| Mar 15, 2000 |
|
Undisclosed amount |
| Jan 12, 2000 |
|
Undisclosed amount |
