When dxzb-tv is the call sign what is the power kw?
CREATE TABLE "ibc_tv_stations" (
  "branding" text,
  "callsign" text,
  "ch_num" text,
  "power_k_w" text,
  "station_type" text,
  "location_transmitter_site" text
);
SELECT "power_k_w" FROM "ibc_tv_stations" WHERE "callsign"='DXZB-TV';