Which Number of vehicles has a Type designation of u5-25 (bi-directional)?
CREATE TABLE "high_floor_versions" (
  "city" text,
  "operator" text,
  "type_designation" text,
  "number_of_vehicles" real,
  "width" text
);
SELECT "number_of_vehicles" FROM "high_floor_versions" WHERE "type_designation"='u5-25 (bi-directional)';