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_name_96 ( est VARCHAR, league VARCHAR, state_province VARCHAR, city VARCHAR )

### Question ###
In what year was the NFL team in chicago illinois established?

### Accurate SQL ###

SELECT est FROM table_name_96 WHERE state_province = "illinois" AND city = "chicago" AND league = "nfl"