What region has 57 vehicles?
CREATE TABLE "list_of_trolleybus_systems_in_russia" (
  "region" text,
  "location" text,
  "from" text,
  "depots_12_09" real,
  "routes_12_09" real,
  "vehicles_12_09" real
);
SELECT "region" FROM "list_of_trolleybus_systems_in_russia" WHERE "vehicles_12_09"=57;