user: Question: What is the total membership for the metropolitan area in the city of Manchester?
Columns: ['City', 'County', 'Region', 'Local authority', 'Type', 'Population', 'Urban area', 'Metropolitan area']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'real', 'real']
Sample row: ['Birmingham', 'West Midlands', 'West Midlands', 'Birmingham City Council', 'Metropolitan borough', 1073000.0, 2284093.0, 3683000.0]
SQL:

assistant: SELECT "Metropolitan area" FROM "Table" WHERE "City" = 'Manchester';