Name the average ERP W when it has a city of license of pound, virginia and frequency mhz more than 91.3
CREATE TABLE "broadcast_translators_of_wise_fm" (
  "call_sign" text,
  "frequency_m_hz" real,
  "city_of_license" text,
  "erp_w" real,
  "fcc_info" text
);
SELECT AVG("erp_w") FROM "broadcast_translators_of_wise_fm" WHERE "city_of_license"='pound, virginia' AND "frequency_m_hz">91.3;