user: Question: Which Class has Laps of 31?
Columns: ['Year', 'Team', 'Co-Drivers', 'Class', 'Laps', 'Pos.', 'Class Pos.']
Types: ['real', 'text', 'text', 'text', 'real', 'text', 'text']
Sample row: [1995.0, 'Venturi Automobiles', 'Paul Belmondo Arnaud Trévisiol', 'GT1', 193.0, 'NC', 'NC']
SQL:

assistant: SELECT "Class" FROM "Table" WHERE "Laps" = 31.0;