user: Question: What champion has 1981 as the year?
Columns: ['Year', 'Date Final', 'Venue', 'Prize Money', 'Champion', 'Runner-up', 'Score in final', 'Commercial name']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['1989', 'Apr 26-30', 'Atlanta', '$500,000', 'Andre Agassi', 'Michael Chang', '6–3, 6–2', 'AT&T Challenge of Champions']
SQL:

assistant: SELECT "Champion" FROM "Table" WHERE "Year" = '1981';