| Date | Acquired | Amount |
|---|---|---|
| Jan 30, 2017 |
|
$ 1,600,000,000 |
| Aug 28, 2015 |
|
Undisclosed amount |
| Aug 13, 2015 |
|
$ 600,000,000 |
| Aug 01, 2005 |
|
Undisclosed amount |
