| Date | Acquired | Amount |
|---|---|---|
| Jul 29, 2014 |
|
Undisclosed amount |
| Jun 14, 2011 |
|
Undisclosed amount |
| Aug 23, 2006 |
|
$ 770,000,000 |
| Oct 21, 2004 |
|
Undisclosed amount |
| Sep 06, 2002 |
|
$ 50,000,000 |
| Feb 07, 2001 |
|
Undisclosed amount |
| May 11, 1999 |
|
$ 85,000,000 |
| May 20, 1998 |
|
$ 300,000,000 |
