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:
| Week | Date | TV Time | Opponent | Result |
| --- | --- | --- | --- | --- |
| 1.0 | September 6, 1998 | CBS 4:00 pm ET | at San Diego Chargers | L 16–14 |
| 2.0 | September 13, 1998 | CBS 1:00 pm ET | at Miami Dolphins | L 13–7 |
| 3.0 | September 20, 1998 | FOX 1:00 pm ET | St. Louis Rams | L 34–33 |
| 4.0 | Bye | Bye | Bye | Bye |
| 5.0 | October 4, 1998 | FOX 1:00 pm ET | San Francisco 49ers | W 26–21 |
| 6.0 | October 11, 1998 | CBS 1:00 pm ET | at Indianapolis Colts | W 31–24 |
| 7.0 | October 18, 1998 | CBS 1:00 pm ET | Jacksonville Jaguars | W 17–16 |
| 8.0 | October 25, 1998 | ESPN 8:15 pm ET | at Carolina Panthers | W 30–14 |
| 9.0 | November 1, 1998 | CBS 1:00 pm ET | Miami Dolphins | W 30–24 |
| 10.0 | November 8, 1998 | CBS 4:15 pm ET | at New York Jets | L 34–12 |
| 11.0 | November 15, 1998 | CBS 1:00 pm ET | New England Patriots | W 13–10 |
| 12.0 | November 22, 1998 | CBS 1:00 pm ET | Indianapolis Colts | W 34–11 |
| 13.0 | November 29, 1998 | CBS 4:15 pm ET | at New England Patriots | L 25–21 |
| 14.0 | December 6, 1998 | CBS 1:00 pm ET | at Cincinnati Bengals | W 33–20 |
| 15.0 | December 13, 1998 | CBS 1:00 pm ET | Oakland Raiders | W 44–21 |
| 16.0 | December 19, 1998 | CBS 12:30 pm ET | New York Jets | L 17–10 |
| 17.0 | December 27, 1998 | CBS 1:00 pm ET | at New Orleans Saints | W 45–33 |
Question:
How many weeks has the opponent been san francisco 49ers?
Answer:
1.0