user: Question: For a year earlier than 1991 and a reynard 91d chassis, what's the highest points?
Columns: ['Year', 'Entrant', 'Chassis', 'Engine', 'Tyres', 'Points']
Types: ['real', 'text', 'text', 'text', 'text', 'real']
Sample row: [1987.0, 'BS Automotive', 'Lola T87/50', 'Ford Cosworth', 'A', 0.0]
SQL:

assistant: SELECT MAX("Points") FROM "Table" WHERE "Chassis" = 'reynard 91d' AND "Year" < 1991.0;