| Date | Acquired | Amount |
|---|---|---|
| Mar 21, 2011 |
|
$ 77,000,000 |
| Jun 01, 2009 |
|
Undisclosed amount |
| Apr 30, 2009 |
|
$ 90,000,000 |
| Oct 24, 2007 |
|
$ 57,000,000 |
