How many cities had a census of 400000 in 1940?
CREATE TABLE "urban_population_in_overseas_territories" (
  "rank" real,
  "city" text,
  "1890_census" text,
  "1910_census" real,
  "1920_census" real,
  "1930_census" real,
  "1940_census" real
);
SELECT COUNT("rank") FROM "urban_population_in_overseas_territories" WHERE "1940_census"=400000;