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

### Instruction:
In what Year of Census or Estimate is the Toronto Population larger than 1,556,396?

### Inputs:
table_name: table, columns: ['Rank', 'City', 'Population', 'Year of Census or Estimate', 'Country']

### Response:
SELECT SUM Year of Census or Estimate FROM table WHERE Population > 1,556,396 AND City = toronto