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: Jim Martin | Republican: Saxby Chambliss | Lead Margin |
| --- | --- | --- | --- | --- |
| Public Policy Polling | November 2, 2008 | 46% | 48% | 2.0 |
| Survey USA | November 2, 2008 | 44% | 48% | 4.0 |
| Rasmussen Reports | October 30, 2008 | 43% | 48% | 5.0 |
| Rasmussen Reports | October 22, 2008 | 45% | 47% | 2.0 |
| Survey USA | October 12, 2008 | 43% | 46% | 3.0 |
| Rasmussen Reports | October 7, 2008 | 44% | 50% | 6.0 |
| Research 2000/Daily Kos | October 1, 2008 | 44% | 45% | 1.0 |
| Survey USA | September 29, 2008 | 44% | 46% | 2.0 |
| Rasmussen Reports | September 16, 2008 | 43% | 50% | 7.0 |
| Survey USA | September 14-September 16, 2008 | 36% | 53% | 17.0 |
| Strategic Vision | September 7-September 9, 2008 | 36% | 54% | 16.0 |
| Rasmussen Reports | August 14, 2008 | 44% | 50% | 6.0 |
| Rasmussen Reports | July 17, 2008 | 40% | 51% | 11.0 |
| Strategic Vision | June 27-June 29, 2008 | 28% | 57% | 29.0 |
| Rasmussen Reports | June 26, 2008 | 39% | 52% | 13.0 |
| Rasmussen Reports | June 4, 2008 | 36% | 52% | 16.0 |
| Rasmussen Reports | May 6, 2008 | 33% | 54% | 21.0 |
Question:
How many times did Saxby Chambliss have a lead margin of 21?
Answer:
1.0