| December 13, 2013 | Gilder Gagnon Howe & CO, LLC | 0.48% | still open |
| September 6, 2013 | Gilder Gagnon Howe & CO, LLC | 0.58% | still open |
| August 13, 2013 | Barrington Wilshire LLC | 0.30% | still open |
| August 9, 2013 | Barrington Wilshire LLC | 0.66% | still open |
| August 6, 2013 | Blackrock Investment Management (UK) Limited | 0.43% | still open |
| August 2, 2013 | Blackrock Investment Management (UK) Limited | 0.55% | still open |
| July 31, 2013 | Blackrock Investment Management (UK) Limited | 0.69% | still open |
| July 30, 2013 | Barrington Wilshire LLC | 0.79% | still open |
| July 29, 2013 | Blackrock Investment Management (UK) Limited | 0.79% | still open |
| July 26, 2013 | Barrington Wilshire LLC | 0.87% | still open |
| July 24, 2013 | Barrington Wilshire LLC | 0.96% | still open |
| July 24, 2013 | Blackrock Investment Management (UK) Limited | 0.88% | still open |
| July 17, 2013 | Blackrock Investment Management (UK) Limited | 0.98% | still open |
| July 12, 2013 | Blackrock Investment Management (UK) Limited | 1.09% | still open |
| July 10, 2013 | Barrington Wilshire LLC | 1.06% | still open |
| July 8, 2013 | Barrington Wilshire LLC | 1.27% | still open |
| July 2, 2013 | Barrington Wilshire LLC | 1.40% | still open |
| June 25, 2013 | Blackrock Investment Management (UK) Limited | 1.18% | still open |
| May 17, 2013 | Blackrock Investment Management (UK) Limited | 1.20% | still open |
| April 29, 2013 | Barrington Wilshire LLC | 1.47% | still open |
| January 29, 2013 | Barrington Wilshire LLC | 1.60% | still open |
| January 29, 2013 | Blackrock Investment Management (UK) Limited | 1.19% | still open |
| January 25, 2013 | Barrington Wilshire LLC | 1.64% | still open |
| January 23, 2013 | Barrington Wilshire LLC | 1.79% | still open |
| December 14, 2012 | Blackrock Investment Management (UK) Limited | 1.28% | still open |
| December 5, 2012 | Blackrock Investment Management (UK) Limited | 1.39% | still open |
| December 3, 2012 | Blackrock Investment Management (UK) Limited | 1.47% | still open |
| November 30, 2012 | Blackrock Investment Management (UK) Limited | 1.51% | still open |
| November 29, 2012 | Blackrock Investment Management (UK) Limited | 1.63% | still open |
| November 26, 2012 | Blackrock Investment Management (UK) Limited | 1.79% | still open |
| November 21, 2012 | Blackrock Investment Management (UK) Limited | 1.85% | still open |
| November 8, 2012 | Blackrock Investment Management (UK) Limited | 1.90% | still open |
| November 1, 2012 | Barrington Wilshire LLC | 1.92% | still open |
| November 1, 2012 | Blackrock Investment Management (UK) Limited | 1.86% | still open |