What was the average round when he had a 3-0 record?
CREATE TABLE "mixed_martial_arts_record" (
  "res" text,
  "record" text,
  "opponent" text,
  "method" text,
  "round" real,
  "time" text,
  "location" text
);
SELECT AVG("round") FROM "mixed_martial_arts_record" WHERE "record"='3-0';