How many winning drivers are there when the winning team is Bryan herta autosport?
CREATE TABLE "race_results" (
  "rd" text,
  "race" text,
  "pole_position" text,
  "fastest_lap" text,
  "most_laps_led" text,
  "winning_driver" text,
  "winning_team" text,
  "report" text
);
SELECT COUNT("winning_driver") FROM "race_results" WHERE "winning_team"='Bryan Herta Autosport';