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 | Tournament | Surface | Opponent in the final | Score |
| --- | --- | --- | --- | --- |
| 1998.0 | Germany F13 | Clay | Mehdi Tahiri | 6–3, 7–6 |
| 1998.0 | Budva | Clay | Fredrik Jonsson | 3–6, 6–3, 6–2 |
| 2002.0 | Sofia | Clay | Werner Eschauer | 6–0, 6–3 |
| 2003.0 | San Remo | Clay | Werner Eschauer | 6–4, 6–2 |
| 2003.0 | Weiden | Clay | Björn Phau | 2–6, 6–4, 6–1 |
| 2004.0 | Kish Island | Clay | Mathieu Montcourt | 7–6(3), 6–1 |
| 2005.0 | Santiago | Clay | Adrián García | 7–6(3), 4–6, 6–2 |
| 2005.0 | Olbia | Clay | Alessio di Mauro | 6–4, 7–6(3) |
Question:
Which Surface has a Tournament of olbia?
Answer:
Clay