Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Market Rank & City of license /Market | Station | Channel TV / DT | Owned since | Affiliation |
| --- | --- | --- | --- | --- |
| 1. New York City | WABC-TV a station built and signed-on by ABC | 7 / 7 | 1948.0 | ABC |
| 2. Los Angeles | KABC-TV | 7 / 7 | 1949.0 | ABC |
| 3. Chicago | WLS-TV | 7 / 44 | 1948.0 | ABC |
| 6. San Francisco - Oakland - San Jose | KGO-TV | 7 / 7 | 1949.0 | ABC |
| 10. Houston | KTRK-TV | 13 / 13 | 1986.0 | ABC |
| 24. Durham - Raleigh - Fayetteville | WTVD | 11 / 11 | 1986.0 | ABC |
Question:
When was the station WLS-TV owned since?
Answer:
1948.0