user: Question: Name the total number of serial number for 24 wd no
Columns: ['LMS No.', 'WD No.', 'Builder', 'Serial No.', 'Date built']
Types: ['real', 'real', 'text', 'real', 'real']
Sample row: [7620.0, 23.0, 'William Beardmore & Co.', 368.0, 1928.0]
SQL:

assistant: SELECT COUNT("Serial No.") FROM "Table" WHERE "WD No." = 24.0;