CREATE TABLE table_64747 ("Team" TEXT, "Winners" FLOAT, "Runners-up" FLOAT, "Years won" TEXT, "Years runner-up" TEXT)

What year(s) was Duisburg runner-up?
SELECT "Years runner-up" FROM table_64747 WHERE "Team" = 'duisburg'
SELECT "Years runner-up" FROM "table_64747" WHERE "Team" = 'duisburg'