What were the average launches for Ariane 5 and 0 partial failures?
CREATE TABLE "by_type" (
  "rocket" text,
  "country" text,
  "family" text,
  "launches" real,
  "successes" real,
  "failures" real,
  "partial_failures" real
);
SELECT AVG("launches") FROM "by_type" WHERE "rocket"='ariane 5' AND "partial_failures"<0;