How many NHL teams are there in the Phoenix, Arizona area?
CREATE TABLE "overview_by_city" (
  "metropolitan_area" text,
  "media_market_ranking" real,
  "hosted_4_teams_since" real,
  "nfl_team_s" text,
  "mlb_team_s" text,
  "nba_team_s" text,
  "nhl_team_s" text
);
SELECT COUNT("nhl_team_s") FROM "overview_by_city" WHERE "metropolitan_area"='Phoenix, Arizona';