user: Question: What is the transfer window for the player whose status was Loan ended?
Columns: ['Name', 'Country', 'Status', 'Moving to', 'Transfer window', 'Transfer fee']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Akın', 'TUR', 'Contract ended', 'Kocaelispor', 'Summer', 'Free']
SQL:

assistant: SELECT "Transfer window" FROM "Table" WHERE "Status" = 'Loan ended';