user: Question: How many people vacated to successor Dave E. Satterfield, Jr. (D)?
Columns: ['District', 'Vacator', 'Reason for change', 'Successor', 'Date successor seated']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Virginia 3rd', 'Andrew Jackson Montague (D)', 'Died January 24, 1937', 'Dave E. Satterfield, Jr. (D)', 'November 2, 1937']
SQL:

assistant: SELECT COUNT("Vacator") FROM "Table" WHERE "Successor" = 'Dave E. Satterfield, Jr. (D)';