| Date | Acquired | Amount |
|---|---|---|
| Oct 11, 2017 |
|
Undisclosed amount |
| May 18, 2016 |
|
$ 940,000,000 |
| Jan 11, 2016 |
|
$ 135,000,000 |
| Aug 07, 2013 |
|
Undisclosed amount |
| Nov 05, 2012 |
|
Undisclosed amount |
| Dec 02, 2011 |
|
Undisclosed amount |
| Sep 19, 2011 |
|
$ 80,000,000 |
| Feb 15, 2011 |
|
Undisclosed amount |
| Jun 10, 2010 |
|
$ 29,000,000 |
| Nov 23, 2009 |
|
$ 22,000,000 |
| Jun 01, 2009 |
|
Undisclosed amount |
| Jul 02, 2007 |
|
$ 281,000,000 |
| Apr 28, 2006 |
|
$ 13,000,000 |
