user: Question: Which year opened is located in West Mifflin, Pennsylvania?
Columns: ['Coaster Name', 'Park', 'Location', 'Track', 'Builder', 'Year Opened']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['American Eagle', 'Six Flags Great America', 'Gurnee, Illinois', 'Wooden', 'Intamin', '1981']
SQL:

assistant: SELECT "Year Opened" FROM "Table" WHERE "Location" = 'West Mifflin, Pennsylvania';