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:
| Round | Circuit | Date | Pole Position | Fastest Lap | Winning Driver | Winning Team |
| --- | --- | --- | --- | --- | --- | --- |
| 1.0 | Autodromo Nazionale Monza | 30 March | Eric Salignon | José María López | Augusto Farfus | RC Motorsport |
| 2.0 | Masaryk Circuit , Brno | 14 April | Ronnie Quintarelli | Ronnie Quintarelli | Augusto Farfus | RC Motorsport |
| 3.0 | Circuit de Nevers Magny-Cours | 29 April | Julien Pressac | Ryan Briscoe | Bruno Spengler | Graff Racing |
| 4.0 | Silverstone Circuit | 5 May | Augusto Farfus | Augusto Farfus | Augusto Farfus | RC Motorsport |
| 5.0 | Circuit Zolder | 18 May | Augusto Farfus | Ronnie Quintarelli | Ronnie Quintarelli | Cram Competition |
| 6.0 | Hungaroring | 29 July | Augusto Farfus | César Campaniço | Augusto Farfus | RC Motorsport |
| 7.0 | A1 Ring , Spielberg | 24 August | Robert Kubica | Eric Salignon | Eric Salignon | Graff Racing |
| 8.0 | Nürburgring | 8 September | José María López | Marc Benz | Marc Benz | Jenzer Motorsport |
| 9.0 | Circuito del Jarama , Madrid | 28 September | César Campaniço | César Campaniço | Ryan Briscoe | Prema Powerteam |
Question:
On what date(s) was the winning team Prema Powerteam?
Answer:
28 September