CREATE TABLE table_44656 ("Nat." TEXT, "Name" TEXT, "Moving from" TEXT, "Type" TEXT, "Transfer window" TEXT, "Ends" TEXT)

What's the transfer window that ends in 2012?
SELECT "Transfer window" FROM table_44656 WHERE "Ends" = '2012'
SELECT "Transfer window" FROM "table_44656" WHERE "Ends" = '2012'