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 | Opponent | Result | Attendance |
| --- | --- | --- | --- | --- |
| 1.0 | September 6, 1981 | at New York Giants | W 24–10 | 72459.0 |
| 2.0 | September 13, 1981 | New England Patriots | W 13–3 | 71089.0 |
| 3.0 | September 17, 1981 | at Buffalo Bills | W 20–14 | 78331.0 |
| 4.0 | September 27, 1981 | Washington Redskins | W 36–13 | 70664.0 |
| 5.0 | October 5, 1981 | Atlanta Falcons | W 16–13 | 71488.0 |
| 6.0 | October 11, 1981 | at New Orleans Saints | W 31–14 | 52728.0 |
| 7.0 | October 18, 1981 | at Minnesota Vikings | L 35–23 | 45459.0 |
| 8.0 | October 25, 1981 | Tampa Bay Buccaneers | W 20–10 | 70714.0 |
| 9.0 | November 1, 1981 | Dallas Cowboys | L 17–14 | 72111.0 |
| 10.0 | November 8, 1981 | at St. Louis Cardinals | W 52–10 | 48421.0 |
| 11.0 | November 15, 1981 | Baltimore Colts | W 38–13 | 68618.0 |
| 12.0 | November 22, 1981 | New York Giants | L 20–10 | 66827.0 |
| 13.0 | November 30, 1981 | at Miami Dolphins | L 13–10 | 67797.0 |
| 14.0 | December 6, 1981 | at Washington Redskins | L 15–13 | 52206.0 |
| 15.0 | December 13, 1981 | at Dallas Cowboys | L 21–10 | 64955.0 |
| 16.0 | December 20, 1981 | St. Louis Cardinals | W 38–0 | 56656.0 |
Question:
What is the average Attendance, when the Date is September 17, 1981?
Answer:
78331.0