user: Question: How many incumbents were first elected in 1930?
Columns: ['District', 'Incumbent', 'Party', 'First elected', 'Result', 'Candidates']
Types: ['text', 'text', 'text', 'real', 'text', 'text']
Sample row: ['Virginia 1', 'S. Otis Bland', 'Democratic', 1918.0, 'Re-elected', 'S. Otis Bland (D) Unopposed']
SQL:

assistant: SELECT COUNT("Party") FROM "Table" WHERE "First elected" = 1930.0;