| Date | Acquired | Amount |
|---|---|---|
| Jul 31, 2015 | $ 230,000,000 | |
| Jul 24, 2015 | $ 23,000,000 | |
| Nov 21, 2014 | Undisclosed amount | |
| Nov 11, 2014 | $ 640,000,000 | |
| Oct 03, 2014 | $ 30,000,000 | |
| Sep 22, 2014 | Undisclosed amount | |
| Sep 07, 2014 | Undisclosed amount | |
| Aug 15, 2014 | Undisclosed amount | |
| Aug 12, 2014 | Undisclosed amount | |
| Aug 12, 2014 | Undisclosed amount | |
| Jul 21, 2014 | $ 200,000,000 | |
| Jul 11, 2014 | Undisclosed amount | |
| May 14, 2014 | Undisclosed amount | |
| May 13, 2014 | Undisclosed amount | |
| Mar 05, 2014 | Undisclosed amount | |
| Feb 13, 2014 | Undisclosed amount | |
| Feb 11, 2014 | Undisclosed amount | |
| Jan 30, 2014 | Undisclosed amount | |
| Jan 28, 2014 | Undisclosed amount | |
| Jan 24, 2014 | Undisclosed amount | |
| Jan 24, 2014 | Undisclosed amount | |
| Jan 21, 2014 | Undisclosed amount | |
| Jan 07, 2014 | $ 80,000,000 | |
| Dec 17, 2013 | Undisclosed amount | |
| Dec 09, 2013 | Undisclosed amount | |
| Dec 06, 2013 | Undisclosed amount | |
| Dec 03, 2013 | Undisclosed amount | |
| Dec 02, 2013 | Undisclosed amount | |
| Oct 23, 2013 | Undisclosed amount | |
| Oct 13, 2013 | Undisclosed amount | |
| Oct 01, 2013 | Undisclosed amount | |
| Aug 23, 2013 | Undisclosed amount | |
| Aug 01, 2013 | $ 65,000,000 | |
| Jul 31, 2013 | Undisclosed amount | |
| Jul 18, 2013 | Undisclosed amount | |
| Jul 17, 2013 | Undisclosed amount | |
| Jul 03, 2013 | $ 48,000,000 | |
| Jul 02, 2013 | $ 50,000,000 | |
| Jul 02, 2013 | Undisclosed amount | |
| Jun 13, 2013 | Undisclosed amount | |
| Jun 12, 2013 | Undisclosed amount | |
| May 23, 2013 | Undisclosed amount | |
| May 20, 2013 | $ 1,100,000,000 | |
| May 10, 2013 | Undisclosed amount | |
| May 09, 2013 | Undisclosed amount | |
| May 01, 2013 | $ 10,000,000 | |
| Mar 25, 2013 | Undisclosed amount | |
| Mar 20, 2013 | Undisclosed amount | |
| Feb 12, 2013 | Undisclosed amount | |
| Jan 22, 2013 | Undisclosed amount | |
| Dec 04, 2012 | Undisclosed amount | |
| Oct 25, 2012 | Undisclosed amount | |
| Nov 01, 2011 | $ 270,000,000 | |
| Apr 25, 2011 | Undisclosed amount | |
| Oct 05, 2010 | Undisclosed amount | |
| May 25, 2010 | Undisclosed amount | |
| May 18, 2010 | $ 90,000,000 | |
| Mar 17, 2010 | Undisclosed amount | |
| Feb 26, 2010 | $ 164,000,000 | |
| May 09, 2008 | Undisclosed amount | |
| Apr 09, 2008 | Undisclosed amount | |
| Feb 04, 2008 | $ 40,000,000 | |
| Jan 31, 2008 | $ 160,000,000 | |
| Sep 04, 2007 | $ 300,000,000 | |
| Jun 20, 2007 | $ 100,000,000 | |
| Apr 29, 2007 | $ 850,000,000 | |
| Jan 09, 2007 | $ 10,000,000 | |
| Nov 17, 2006 | Undisclosed amount | |
| Nov 16, 2006 | Undisclosed amount | |
| Oct 17, 2006 | Undisclosed amount | |
| Sep 27, 2006 | Undisclosed amount | |
| Apr 18, 2006 | Undisclosed amount | |
| Jan 16, 2006 | Undisclosed amount | |
| Dec 01, 2005 | Undisclosed amount | |
| Oct 05, 2005 | Undisclosed amount | |
| Jul 25, 2005 | Undisclosed amount | |
| Jun 15, 2005 | Undisclosed amount | |
| Apr 12, 2005 | Undisclosed amount | |
| Mar 20, 2005 | Undisclosed amount | |
| Mar 04, 2005 | Undisclosed amount | |
| Feb 01, 2005 | $ 93,000,000 | |
| Oct 01, 2004 | Undisclosed amount | |
| Sep 14, 2004 | $ 160,000,000 | |
| Sep 01, 2004 | Undisclosed amount | |
| Aug 06, 2004 | Undisclosed amount | |
| Jul 12, 2004 | Undisclosed amount | |
| Mar 26, 2004 | Undisclosed amount | |
| Jan 01, 2004 | Undisclosed amount | |
| Oct 29, 2003 | Undisclosed amount | |
| Feb 02, 2003 | $ 100,000,000 | |
| Dec 23, 2002 | $ 235,000,000 | |
| Jan 08, 2002 | Undisclosed amount | |
| Jun 28, 2001 | $ 12,000,000 | |
| Apr 11, 2001 | $ 30,000,000 | |
| Feb 26, 2001 | $ 145,000,000 | |
| Jun 30, 2000 | $ 8,900,000 | |
| Jun 28, 2000 | $ 432,000,000 | |
| Mar 23, 2000 | Undisclosed amount | |
| Mar 01, 2000 | Undisclosed amount | |
| Jul 02, 1999 | $ 80,000,000 |