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:
| Team | Outgoing manager | Manner of departure | Date of vacancy | Replaced by | Date of appointment |
| --- | --- | --- | --- | --- | --- |
| Siena | Mario Beretta | Contract expired | 27 May 2008 | Marco Giampaolo | 27 May 2008 |
| Cagliari | Davide Ballardini | Contract expired | 27 May 2008 | Massimiliano Allegri | 29 May 2008 |
| Internazionale | Roberto Mancini | Sacked | 29 May 2008 | José Mourinho | 2 June 2008 |
| Lecce | Giuseppe Papadopulo | Contract expired | 23 June 2008 | Mario Beretta | 23 June 2008 |
| Palermo | Stefano Colantuono | Sacked | 4 September 2008 | Davide Ballardini | 4 September 2008 |
| Bologna | Daniele Arrigoni | Sacked | 3 November 2008 | Siniša Mihajlović | 3 November 2008 |
| Chievo Verona | Giuseppe Iachini | Sacked | 4 November 2008 | Domenico Di Carlo | 4 November 2008 |
| Torino | Gianni De Biasi | Sacked | 8 December 2008 | Walter Novellino | 8 December 2008 |
| Reggina | Nevio Orlandi | Sacked | 16 December 2008 | Giuseppe Pillon | 16 December 2008 |
| Reggina | Giuseppe Pillon | Sacked | 25 January 2009 | Nevio Orlandi | 25 January 2009 |
| Lecce | Mario Beretta | Sacked | 9 March 2009 | Luigi De Canio | 9 March 2009 |
| Napoli | Edoardo Reja | Sacked | 10 March 2009 | Roberto Donadoni | 10 March 2009 |
| Torino | Walter Novellino | Sacked | 24 March 2009 | Giancarlo Camolese | 24 March 2009 |
| Bologna | Siniša Mihajlović | Sacked | 14 April 2009 | Giuseppe Papadopulo | 14 April 2009 |
| Juventus | Claudio Ranieri | Sacked | 18 May 2009 | Ciro Ferrara | 18 May 2009 |
Question:
What was the manner of departure for the outgoing manager, davide ballardini?
Answer:
Contract expired