Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Poll Source | Dates administered | Democrat: Vivian Davis Figures | Republican: Jeff Sessions | Lead Margin |
| --- | --- | --- | --- | --- |
| Survey USA | October 28, 2008 | 32% | 65% | 33.0 |
| Survey USA | October 9, 2008 | 33% | 64% | 31.0 |
| Rasmussen Reports | September 22, 2008 | 30% | 59% | 29.0 |
| SurveyUSA | September 16–17, 2008 | 31% | 66% | 35.0 |
| Rasmussen Reports | July 31, 2008 | 31% | 58% | 27.0 |
| Rasmussen Reports | June 30, 2008 | 34% | 58% | 24.0 |
| Rasmussen Reports | May 27, 2008 | 29% | 62% | 33.0 |
| Rasmussen Reports | April 2, 2008 | 36% | 57% | 21.0 |
| Rasmussen Reports | November 14, 2007 | 30% | 62% | 32.0 |
| SurveyUSA | August 25–27, 2007 | 37% | 59% | 22.0 |
Question:
What is the poll source when Jeff Sessions is at 58% and the date administered is July 31, 2008?
Answer:
Rasmussen Reports