| Year | Qtr | # Shares | Change |
|---|---|---|---|
| 2013 | Q3 | 0 | Liquidated |
| 2013 | Q2 | 1,080,000 | +56,300 |
| 2013 | Q1 | 1,023,700 | +49,600 |
| 2012 | Q4 | 974,100 | +103,100 |
| 2012 | Q3 | 871,000 | +536,700 |
| 2012 | Q2 | 334,300 | -113,200 |
| 2012 | Q1 | 447,500 | -476,500 |
| 2011 | Q4 | 924,000 | +101,900 |
| 2011 | Q3 | 822,100 | +544,700 |
| 2011 | Q2 | 277,400 | -501,800 |
| 2011 | Q1 | 779,200 |