user: Question: How much Withdrawn has a Number of 42, and a Previous Number(s) larger than 68178?
Columns: ['Number', 'Previous Number(s)', 'Previous Class', 'Converted', 'Withdrawn', 'Disposal']
Types: ['text', 'real', 'text', 'real', 'real', 'text']
Sample row: ['31 (1st)', 68383.0, 'J66', 1952.0, 1959.0, 'Scrapped (1959)']
SQL:

assistant: SELECT SUM("Withdrawn") FROM "Table" WHERE "Number" = '42' AND "Previous Number(s)" > 68178.0;