CREATE TABLE table_31018 ("Team" TEXT, "Contest and round" TEXT, "Opponent" TEXT, "1st leg score*" TEXT, "2nd leg score**" TEXT, "Aggregate score" TEXT)

what is the aggregate score for the europa league play off round contest and round
SELECT "Aggregate score" FROM table_31018 WHERE "Contest and round" = 'Europa League Play Off Round'
SELECT "Aggregate score" FROM "table_31018" WHERE "Contest and round" = 'Europa League Play Off Round'