| Date | Acquired | Amount |
|---|---|---|
| Nov 17, 2013 |
|
Undisclosed amount |
| Mar 16, 2012 |
|
Undisclosed amount |
| Feb 16, 2011 |
|
Undisclosed amount |
| Jun 30, 2010 |
|
$ 560,000,000 |
| Oct 01, 2009 |
|
Undisclosed amount |
| Jul 27, 2009 |
|
Undisclosed amount |
| Jul 13, 2009 |
|
Undisclosed amount |
| Apr 15, 2009 |
|
$ 500,000,000 |
| Sep 24, 2008 |
|
$ 2,600,000,000 |
