How many times did the team achieve an overrall record of mu, 21-19?
CREATE TABLE "record_vs_other_opponents_at_least_15_ga" (
  "missouri_vs" text,
  "overall_record" text,
  "at_columbia" text,
  "at_opponents_venue" text,
  "at_neutral_site" text,
  "last_5_meetings" text,
  "last_10_meetings" text,
  "current_streak" text
);
SELECT COUNT("last_5_meetings") FROM "record_vs_other_opponents_at_least_15_ga" WHERE "overall_record"='MU, 21-19';