CREATE TABLE table_31660 ("Date" TEXT, "Result" TEXT, "Opponent" TEXT, "Method" TEXT, "Round" FLOAT)

When did the opponent knockout Barry Prior in more than 2 rounds?
SELECT "Date" FROM table_31660 WHERE "Method" = 'knockout' AND "Round" > '2' AND "Opponent" = 'barry prior'
SELECT "Date" FROM "table_31660" WHERE "Method" = 'knockout' AND "Opponent" = 'barry prior' AND "Round" > '2'