Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
What is the average market value with a revenue greater than 6.2, a Company of national bank of greece, and a Rank smaller than 1?

### Inputs:
table_name: table, columns: ['Rank', 'Company', 'Revenues (US$ billion)', 'Profit (US$ billion)', 'Assets (US$ billion)', 'Market value (US$ billion)']

### Response:
SELECT AVG Market value (US$ billion) FROM table WHERE Revenues (US$ billion) > 6.2 AND Company = national bank of greece AND Rank < 1