Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_1174162_1 ( date_first_settled_as_a_suburb VARCHAR, median_age__in_2006_ VARCHAR )

### Question ###
What is the date settled for 40 years?

### Accurate SQL ###

SELECT date_first_settled_as_a_suburb FROM table_1174162_1 WHERE median_age__in_2006_ = "40 years"