user: Question: Name the class for 4th position with year before 2006
Columns: ['Year', 'Team', 'Co-Drivers', 'Class', 'Laps', 'Pos.', 'Class Pos.']
Types: ['real', 'text', 'text', 'text', 'real', 'text', 'text']
Sample row: [1999.0, 'Panoz Motorsports', "Johnny O'Connell Max Angelelli", 'LMP', 323.0, '11th', '9th']
SQL:

assistant: SELECT "Class" FROM "Table" WHERE "Pos." = '4th' AND "Year" < 2006.0;