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:
| Episode No. | Airdate | Total Viewers | Share | BBC One Weekly Ranking |
| --- | --- | --- | --- | --- |
| 1.0 | 2 September 2011 | 6114000.0 | 24.2% | 9.0 |
| 2.0 | 9 September 2011 | 5370000.0 | 20.2% | 14.0 |
| 3.0 | 16 September 2011 | 5450000.0 | 21.7% | 11.0 |
| 4.0 | 23 September 2011 | 5210000.0 | 19.5% | 10.0 |
| 5.0 | 29 September 2011 | 5020000.0 | 18.8% | 16.0 |
| 6.0 | 7 October 2011 | 4780000.0 | 16.9% | 17.0 |
Question:
What date did the episode with a weekly ranking of 14 air?
Answer:
9 September 2011