| Date | Open | Close | Volume |
| 2010-03-03 | 39.14 | 37.32 | 3223600 |
| 2010-03-02 | 37.60 | 38.48 | 3551100 |
| 2010-03-01 | 36.24 | 37.32 | 1976600 |
| 2010-02-26 | 35.52 | 35.89 | 1525500 |
| 2010-02-25 | 35.37 | 35.54 | 1378100 |
| 2010-02-24 | 35.62 | 35.93 | 1307100 |
| 2010-02-23 | 36.91 | 35.66 | 1588100 |
| 2010-02-22 | 36.80 | 36.84 | 1850600 |
| 2010-02-19 | 36.39 | 36.82 | 1338000 |
| 2010-02-18 | 35.72 | 36.37 | 1091300 |
| 2010-02-17 | 35.90 | 35.91 | 1578600 |
| 2010-02-16 | 34.77 | 35.72 | 1250100 |
| 2010-02-12 | 33.81 | 35.13 | 2105300 |
| 2010-02-11 | 33.13 | 34.02 | 1247000 |
| 2010-02-10 | 33.47 | 33.13 | 1276500 |
| 2010-02-09 | 31.83 | 33.25 | 2724000 |
| 2010-02-08 | 32.22 | 32.15 | 1328400 |
| 2010-02-05 | 31.60 | 32.13 | 1544800 |
| 2010-02-04 | 32.83 | 31.68 | 1699100 |
| 2010-02-03 | 33.26 | 33.15 | 1239800 |
| 2010-02-02 | 33.23 | 33.35 | 1336300 |
| 2010-02-01 | 32.14 | 33.20 | 1202500 |
| 2010-01-29 | 33.68 | 32.07 | 2284400 |
| 2010-01-28 | 35.15 | 33.44 | 2062600 |
| 2010-01-27 | 35.29 | 35.46 | 1407700 |
| 2010-01-26 | 34.65 | 35.28 | 4410100 |
| 2010-01-25 | 34.03 | 34.30 | 2158700 |
| 2010-01-22 | 34.49 | 33.73 | 2229900 |
| 2010-01-21 | 34.93 | 34.47 | 1168000 |
| 2010-01-20 | 35.11 | 34.79 | 633300 |
| 2010-01-19 | 34.82 | 35.47 | 1088600 |
| 2010-01-15 | 36.00 | 34.86 | 1897400 |
Other Companies: 06-12-2007 | Duke Energy Corporation | 07-24-2007
Duff & Phelps Utility & Corporate Bond Trust Inc. | 07-26-2008 | AEGON N.V.