| Date | Acquired | Amount |
|---|---|---|
| Jan 23, 2017 |
|
$ 929,000,000 |
| Jul 12, 2016 |
|
$ 1,210,000,000 |
| Mar 04, 2016 |
|
$ 1,100,000,000 |
| Jul 14, 2015 |
|
$ 175,000,000 |
