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:
| Date | Pos. | Player | From club | Transfer fee |
| --- | --- | --- | --- | --- |
| Sep. 2008 | FW | Marcello Trotta | Napoli | £750,000 [x] |
| 12 Oct. 2008 | DF | Oliver Nicholas | Arsenal | Free |
| 20 Oct. 2008 | MF | Alex Pla | UD Cornellà | Undisc. |
| 20 Oct. 2008 | MF | Jorge Guinovart | UD Cornellà | Undisc. |
| 17 Feb. 2009 | DF | Jérémy Helan | Rennes | Undisc. |
| 25 Feb. 2009 | GK | Gunnar Nielsen | Blackburn Rovers | Free |
Question:
Which Transfer fee has a From club of blackburn rovers?
Answer:
Free