user: Question: With a Type of 4-6-4T, what is the sum Withdrawn?
Columns: ['Locomotive', 'Type', 'Builder', "Builder's No.", 'Built', 'Entered service', 'Withdrawn']
Types: ['text', 'text', 'text', 'text', 'real', 'real', 'real']
Sample row: ['2', '0-6-0ST', 'Beyer Peacock & Co', '2575', 1884.0, 1884.0, 1938.0]
SQL:

assistant: SELECT SUM("Withdrawn") FROM "Table" WHERE "Type" = '4-6-4T';