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: Carl Levin | Republican: Jack Hoogendyk | Lead Margin |
| --- | --- | --- | --- | --- |
| Rasmussen Reports | October 8, 2008 | 61% | 36% | 25.0 |
| Strategic Vision | September 22-September 24, 2008 | 57% | 29% | 28.0 |
| EPIC-MRA | September 14-September 17, 2008 | 54% | 26% | 28.0 |
| Rasmussen Reports | September 10, 2008 | 57% | 38% | 19.0 |
| Public Policy Polling | September 6-September 7, 2008 | 51% | 36% | 15.0 |
| Strategic Vision | September 5-September 7, 2008 | 58% | 28% | 20.0 |
| EPIC-MRA | August 18-August 21, 2008 | 59% | 27% | 32.0 |
| Rasmussen Reports | August 7, 2008 | 57% | 39% | 18.0 |
| Public Policy Polling | July 23-July 27, 2008 | 54% | 35% | 19.0 |
| Rasmussen Reports | July 10, 2008 | 59% | 36% | 23.0 |
| Public Policy Polling | June 21-June 22, 2008 | 54% | 32% | 22.0 |
| Rasmussen Reports | June 11, 2008 | 55% | 35% | 20.0 |
Question:
What was the smallest lead margin when the source of polls came from Strategic Vision and Democrat Carl Levin had 57%?
Answer:
28.0