user: Question: Name the highest Labour with Lib Dem larger than 21?
Columns: ['Year', 'Labour', 'Lib Dem', 'Green', 'IWCA', 'Independent', 'Conservative']
Types: ['real', 'real', 'real', 'real', 'real', 'real', 'real']
Sample row: [2000.0, 21.0, 21.0, 7.0, 1.0, 0.0, 1.0]
SQL:

assistant: SELECT MAX("Labour") FROM "Table" WHERE "Lib Dem" > 21.0;