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:
| District | Incumbent | Party | First elected | Results |
| --- | --- | --- | --- | --- |
| Oklahoma 1 | John Sullivan | Republican | 2002.0 | Re-elected |
| Oklahoma 2 | Dan Boren | Democratic | 2004.0 | Re-elected |
| Oklahoma 3 | Frank Lucas | Republican | 1994.0 | Re-elected |
| Oklahoma 4 | Tom Cole | Republican | 2002.0 | Re-elected |
| Oklahoma 5 | Ernest Istook | Republican | 1992.0 | Retired to run for Governor Republican hold |
Question:
Incumbent John Sullivan has what as biggest first elected?
Answer:
2002.0