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

### Instruction:
What is the date settled for 40 years?

### Inputs:
table_name: table, columns: ['Suburb', 'Population (in 2008)', 'Median age (in 2006)', 'Mean household size (in 2006)', 'Area (km²)', 'Density (/km²)', 'Date first settled as a suburb', 'Gazetted as a Division Name']

### Response:
SELECT Date first settled as a suburb FROM table WHERE Median age (in 2006) = 40 years