What is the largest number of wickets when there are more than 630 maidens and a best of 7/72?
CREATE TABLE "references" (
  "name" text,
  "career" text,
  "matches" real,
  "overs" real,
  "maidens" real,
  "runs" real,
  "wickets" real,
  "average" real,
  "best" text
);
SELECT MAX("wickets") FROM "references" WHERE "maidens">630 AND "best"='7/72';