What is the inegi code for mexicali with 13,700 km area?
CREATE TABLE "list_of_mexican_municipalities" (
  "inegi_code" real,
  "municipality" text,
  "municipal_seat" text,
  "population_2010" real,
  "area_km2" real
);
SELECT AVG("inegi_code") FROM "list_of_mexican_municipalities" WHERE "municipal_seat"='mexicali' AND "area_km2">'13,700';