Name the total number of ERP W when the call sign is w217bf
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 COUNT("erp_w") FROM "broadcast_translators_of_wise_fm" WHERE "call_sign"='w217bf';