CREATE TABLE table_7712 ("Season" TEXT, "Competition" TEXT, "Round" TEXT, "Opponent" TEXT, "Home" TEXT, "Away" TEXT, "Agg." TEXT)

What was the aggregate total for the match against Koper?
SELECT "Agg." FROM table_7712 WHERE "Opponent" = 'koper'
SELECT "Agg." FROM "table_7712" WHERE "Opponent" = 'koper'