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_2597 ( "Market Rank & City of license /Market" text, "Station" text, "Channel TV / DT" text, "Owned since" real, "Affiliation" text )

### Question ###
When was the station WLS-TV owned since?

### Accurate SQL ###

SELECT "Owned since" FROM table_2597 WHERE "Station" = 'WLS-TV'