user: Question: In what year did Tom Sneva win a race?
Columns: ['Season', 'Race Name', 'Winning Driver', 'Chassis', 'Engine', 'Tires', 'Team']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1973.0, 'Texas 200', 'Al Unser', 'Parnelli', 'Offenhauser', 'Firestone', 'Vels Parnelli Jones']
SQL:

assistant: SELECT "Season" FROM "Table" WHERE "Winning Driver" = 'Tom Sneva';