user: Question: What year(s) was the race status Piston?
Columns: ['Year', 'Car number', 'Start', 'Qual. speed', 'Speed rank', 'Finish', 'Laps completed', 'Laps led', 'Race status', 'Chassis']
Types: ['real', 'real', 'real', 'text', 'real', 'real', 'real', 'real', 'text', 'text']
Sample row: [1963.0, 92.0, 5.0, '149.750', 7.0, 2.0, 200.0, 28.0, 'Running', 'Lotus-Ford 29/3']
SQL:

assistant: SELECT "Year" FROM "Table" WHERE "Race status" = 'Piston';