user: Question: What is the highest number of Seats 2006 held by the communities of Bürger für Groß-Rohrheim Party/Voter Community, with a %2006 less than 21.3?
Columns: ['Parties and voter communities', '% 2006', 'Seats 2006', '% 2001', 'Seats 2001']
Types: ['text', 'real', 'real', 'real', 'real']
Sample row: ['Social Democratic Party of Germany', 54.1, 10.0, 62.5, 14.0]
SQL:

assistant: SELECT MAX("Seats 2006") FROM "Table" WHERE "Parties and voter communities" = 'Bürger für Groß-Rohrheim' AND "% 2006" < 21.3;