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:
| Home team | Home team score | Away team | Away team score | Ground | Date | Crowd |
| --- | --- | --- | --- | --- | --- | --- |
| Geelong | 4.10 (34) | Sydney | 6.11 (47) | Marrara Oval | Friday, 16 February | 8500.0 |
| Port Adelaide | 16.25 (121) | Essendon | 5.12 (42) | Football Park | Saturday, 17 February | 19498.0 |
| Port Adelaide | 17.10 (112) | Sydney | 15.17 (107) | Football Park | Friday, 23 February | 15709.0 |
| Essendon | 12.18 (90) | Geelong | 17.10 (112) | Colonial Stadium | Friday, 23 February | 22829.0 |
| Geelong | 12.15 (87) | Port Adelaide | 16.9 (105) | Colonial Stadium | Saturday, 3 March | 4474.0 |
| Sydney | 11.17 (83) | Essendon | 8.11 (59) | Manuka Oval | Saturday, 3 March | 12358.0 |
Question:
What's the average crowd size that had an away score of 15.17 (107)?
Answer:
15709.0