| Date | Acquired | Amount |
|---|---|---|
| Aug 30, 2017 |
|
Undisclosed amount |
| Apr 04, 2017 |
|
Undisclosed amount |
| Aug 24, 2016 |
|
Undisclosed amount |
| Oct 01, 2015 |
|
Undisclosed amount |
| Jul 31, 2014 |
|
$ 890,000,000 |
| May 19, 2014 |
|
Undisclosed amount |
| May 05, 2013 |
|
Undisclosed amount |
| May 24, 2011 |
|
$ 500,000,000 |
| Mar 08, 2010 |
|
$ 460,000,000 |
| Jul 13, 2004 |
|
£ 280,000,000 |
