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 | Game site | Attendance |
| --- | --- | --- | --- | --- | --- |
| 1.0 | 1979-09-02 | Cleveland Browns | L 25–22 ( OT ) | Shea Stadium | 48472.0 |
| 2.0 | 1979-09-09 | at New England Patriots | L 56–3 | Schafer Stadium | 53113.0 |
| 3.0 | 1979-09-16 | Detroit Lions | W 31–10 | Shea Stadium | 49612.0 |
| 4.0 | 1979-09-23 | at Buffalo Bills | L 46–31 | Rich Stadium | 68731.0 |
| 5.0 | 1979-09-30 | Miami Dolphins | W 33–27 | Shea Stadium | 51496.0 |
| 6.0 | 1979-10-07 | at Baltimore Colts | L 10–8 | Memorial Stadium | 32142.0 |
| 7.0 | 1979-10-15 | Minnesota Vikings | W 14–7 | Shea Stadium | 54479.0 |
| 8.0 | 1979-10-21 | Oakland Raiders | W 28–19 | Shea Stadium | 55802.0 |
| 9.0 | 1979-10-28 | at Houston Oilers | L 27–24 (OT) | The Astrodome | 45825.0 |
| 10.0 | 1979-11-04 | at Green Bay Packers | W 27–22 | Lambeau Field | 54201.0 |
| 11.0 | 1979-11-11 | Buffalo Bills | L 14–12 | Shea Stadium | 50647.0 |
| 12.0 | 1979-11-18 | at Chicago Bears | L 23–13 | Soldier Field | 52635.0 |
| 13.0 | 1979-11-26 | at Seattle Seahawks | L 30–7 | Kingdome | 59977.0 |
| 14.0 | 1979-12-02 | Baltimore Colts | W 30–17 | Shea Stadium | 47744.0 |
| 15.0 | 1979-12-09 | New England Patriots | W 27–26 | Shea Stadium | 45131.0 |
| 16.0 | 1979-12-15 | at Miami Dolphins | W 27–24 | Miami Orange Bowl | 49915.0 |
Question:
What average week has shea stadium as the game site, and 1979-12-09 as the date?
Answer:
15.0