| Date | Acquired | Amount |
|---|---|---|
| Nov 12, 2012 |
|
Undisclosed amount |
| Apr 25, 2011 |
|
Undisclosed amount |
| Dec 28, 2006 |
|
$ 435,000,000 |
| Sep 21, 2006 |
|
$ 72,500,000 |
| Aug 16, 2006 |
|
$ 5,000,000 |
