what's the notes where withdrawn is 1956–57
{'header': ['Number Range', 'Introduced', 'Builder', 'Engine', 'Weight (long tons)', 'Seats', 'Withdrawn', 'Notes'], 'page_title': 'GWR railcars', 'section_title': 'Fleet list', 'caption': 'Fleet list', 'rows': [['1', '1934', 'Park Royal', '1 AEC of hp (kW)', 'long tons (t; short tons)', '69', '1955', 'Prototype railcar'], ['2–4', '1934', 'Park Royal', '2 AEC of hp (kW)', 'long tons (t; short tons)', '44', '1954–1958', 'Buffet fitted'], ['5–7', '1935', 'Gloucester RCW', '2 AEC of hp (kW)', 'long tons (t; short tons)', '70', '1957–59', 'Standard single car'], ['8–9, 13–16', '1936', 'Gloucester RCW', '2 AEC of hp (kW)', 'long tons (t; short tons)', '70', '1957–60', '9 withdrawn in 1946 after fire'], ['10–12', '1936', 'Gloucester RCW', '2 AEC of hp (kW)', 'long tons (t; short tons)', '63', '1956–57', 'Lavatory fitted'], ['17', '1936', 'Gloucester RCW', '2 AEC of hp (kW)', 'long tons (t; short tons)', 'None', '1959', 'Parcels car, capacity long tons (t; short tons)'], ['19–33', '1940–41', 'GWR, Swindon', '2 AEC of hp (kW)', 'long tons (t; short tons)', '48', '1960–62', '33 rebuilt in 1954 to replace 37']]}