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 7, 1981 | at Cleveland Browns | W 44–14 | 78904.0 |
| 2.0 | September 13, 1981 | Detroit Lions | W 28–23 | 51264.0 |
| 3.0 | September 20, 1981 | at Kansas City Chiefs | W 42–31 | 63866.0 |
| 4.0 | September 27, 1981 | at Denver Broncos | L 42–24 | 74822.0 |
| 5.0 | October 4, 1981 | Seattle Seahawks | W 24–10 | 51463.0 |
| 6.0 | October 11, 1981 | Minnesota Vikings | L 33–31 | 50708.0 |
| 7.0 | October 18, 1981 | at Baltimore Colts | W 43–14 | 41921.0 |
| 8.0 | October 25, 1981 | at Chicago Bears | L 20–17 | 52906.0 |
| 9.0 | November 1, 1981 | Kansas City Chiefs | W 22–20 | 51307.0 |
| 10.0 | November 8, 1981 | Cincinnati Bengals | L 40–17 | 51259.0 |
| 11.0 | November 16, 1981 | at Seattle Seahawks | L 44–23 | 58628.0 |
| 12.0 | November 22, 1981 | at Oakland Raiders | W 55–21 | 50199.0 |
| 13.0 | November 29, 1981 | Denver Broncos | W 34–17 | 51533.0 |
| 14.0 | December 6, 1981 | Buffalo Bills | L 28–27 | 51488.0 |
| 15.0 | December 13, 1981 | at Tampa Bay Buccaneers | W 24–23 | 67388.0 |
| 16.0 | December 21, 1981 | Oakland Raiders | W 23–10 | 52279.0 |
Question:
What is the average Week when there were more than 63,866 people in attendance on September 7, 1981?
Answer:
1.0