| Date | Acquired | Amount |
|---|---|---|
| Jan 29, 2016 |
|
Undisclosed amount |
| Dec 10, 2015 |
|
$ 21,500,000 |
| Feb 28, 2014 |
|
Undisclosed amount |
| Feb 01, 2012 |
|
$ 680,000,000 |
| Jul 06, 2006 |
|
$ 230,000,000 |
| Nov 18, 1996 |
|
$ 755,000,000 |
| Aug 20, 1993 |
|
$ 1,000,000,000 |
