user: Question: What is the date for the episode performed by Sue Manchester?
Columns: ['Episode title', 'Subject', 'Music by', 'Lyrics by', 'Performed by', 'First aired']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Elbow Room', 'U.S. territorial expansion', 'Lynn Ahrens', 'Lynn Ahrens', 'Sue Manchester', '1975']
SQL:

assistant: SELECT "First aired" FROM "Table" WHERE "Performed by" = 'Sue Manchester';