WHich Facility ID has a Call sign of wnpr?
CREATE TABLE "stations" (
  "call_sign" text,
  "frequency" text,
  "city_of_license" text,
  "facility_id" real,
  "erp_power_w" real,
  "height_m_ft" text,
  "class" text
);
SELECT AVG("facility_id") FROM "stations" WHERE "call_sign"='wnpr';